Hello (..hello..hello..hello..)

[CP/M User]

"Terry Yager" wrote:

>> Of course, that doesn't mean that I liked
>> the machine, but it proves that I've seen
>> it do more than just be a games
>> machine.

> Well, I'm not a real big C= fan either, but
> I have nothing against them--they're very
> good at doing what they do. The main
> reason I (personally) never cared for
> them is that they didn't have an 80-column
> display, a minimum requirement (IMHO)
> for a serious computer (something I never
> liked about Apple IIs either). OTOH, I
> really do like the 128D, which does have
> 80-column capability, and runs CP/M as
> well.

I didn't realise that it didn't have 80x25
display. Naturally, I agree that this was
essential for serious business users.

Of course this is found on the Amstrad &
the graphics resolution (which is restricted
to 2 colours - excluding Screen Border) is
very detailed (it's possible to create
different shades of colours in this mode
though with the high resolution).

>> Of course the C64 could also run CP/M
>> perhaps not in the same vein as a Z80
>> could, but there were some serious
>> applications available for this machine
>> & even at the time when the original
>> C64 came out, writers felt this was a
>> machine suitable for small businesses.

> The CP/M for the 64 required a plug-in
> card, which contained a real Z80, so
> when you ran CP/M on it you were
> running it on a Z80. The 128 had the
> Z80 built-in, so no extra plug-in
> module was required.

Tell me about it! ;-)

Cheers,
CP/M User.

 

[Terry Yager]

"Terry Yager" wrote:

>> Of course the C64 could also run CP/M
>> perhaps not in the same vein as a Z80
>> could, but there were some serious
>> applications available for this machine
>> & even at the time when the original
>> C64 came out, writers felt this was a
>> machine suitable for small businesses.

> The CP/M for the 64 required a plug-in
> card, which contained a real Z80, so
> when you ran CP/M on it you were
> running it on a Z80. The 128 had the
> Z80 built-in, so no extra plug-in
> module was required.

Tell me about it! ;-)

Cheers,
CP/M User.

I'm not much of an expert on C64s, but as I understand it, the Z80 would switch-out the 6510 in the 64 instead of working along with it, so it doesn't really count as a true co-processor--more of an auxillary or alternate processor. It did use all the rest of the C64's resources tho (memory, I/O, etc.). I think that in the 128 however, the two processors worked in unison. (I could be wrong about this--mebbe some of our C= fans here can shed more light on this).

--T

 

[CP/M User]

"Terry Yager" wrote:

> I'm not much of an expert on C64s, but as I
> understand it, the Z80 would switch-out the
> 6510 in the 64 instead of working along with
> it, so it doesn't really count as a true
> co-processor--more of an auxillary or
> alternate processor.

Yes, I cannot explain how the Z80 worked with
the C64. However, in one of my books it
explains that for machines which can have
another processor available for this, then the
both of them can work together. The computer
they were giving an example which did this, is
one (if not all) of the BBC based computers
which is 6502 based, but can have a Z80
plugged into it. They stated that a program
written using Z80 would use the Z80 processor,
while the 6502 could concentrate on other
hardware like the display & possibly the
other resources, but that the 6502 processor
would have been freed up.

> It did use all the rest of the C64's resources
> tho (memory, I/O, etc.). I think that in the
> 128 however, the two processors worked in
> unison. (I could be wrong about this--mebbe
> some of our C= fans here can shed more light
> on this).

I can't understand why the C128 didn't take off
as well as the C64. I'd guess that if it had the
same hardware restrictions as the C64, then it
wouldn't be a nice choice of a business
machine. One of the advantages of the Amstrad
CPC6128, was that it did have that 80x25 screen
& was used on many occasions for serious
software. Games wise, there were a lot of games
which used the extra 64k (because of the
CPC464/CPC664 users). The 6128 is inbetween a
PCW & a CPC because it's capable of running
CP/M (found on the PCW, the 80x25 display), but
it didn't have 256k (like the PCW base model had,
nor did it boot up CP/M the minute you switched
on the Computer) which is why it's a CPC! ;-)

Commodore I've noticed brought out a series of
Business type machines, so I guess that if the
C128 was compatable with them, then I guess
that was the idea.

To businesses which might of had a PCW, would
have found a CPC6128 a nice machine for the
home, because the Disks were the same 3" &
basically the format was too. The PCW also had
games as well & while they were compatable on
the CPC6128, they weren't compatable with the
other CPCs with 64k (though even after
expanding a 64k Amstrad to 128k - there were
issues with CP/M Plus running on it - CP/M Plus
was what PCWs & CPC6128 could run! 8-)

Cheers,
CP/M User.

 

[Terry Yager]

"Terry Yager" wrote:

> I'm not much of an expert on C64s, but as I
> understand it, the Z80 would switch-out the
> 6510 in the 64 instead of working along with
> it, so it doesn't really count as a true
> co-processor--more of an auxillary or
> alternate processor.

Yes, I cannot explain how the Z80 worked with
the C64. However, in one of my books it
explains that for machines which can have
another processor available for this, then the
both of them can work together. The computer
they were giving an example which did this, is
one (if not all) of the BBC based computers
which is 6502 based, but can have a Z80
plugged into it. They stated that a program
written using Z80 would use the Z80 processor,
while the 6502 could concentrate on other
hardware like the display & possibly the
other resources, but that the 6502 processor
would have been freed up.

The Commodore 64 used the VIC chip in a similar way when running the Z80, to handle the display and other I/O. (The VIC is a kind of processor itself, isn't it?)
Just to bring the thread back on topic, (this is the Tandy forum, right?) The TRS-80 Model 16 had dual processors, it's native mode Z80, and an optional 68000. When the Z80 was in control, the 68000 was switched out, but when in 68000 mode, it used the Z80 as an I/O processor, to speed things up. The 68000 could address more memory than the Z80, so the Z80 would not use all the machines resources. (The Mod 16 could take up to 1Mb, iirc). Another machine I used to have, the Altos 686, was an 80286 based machine which also used a Z80 for I/O. (It also had 3 Z80 DART chips, giving it up to 6 serial ports). I'm not sure exactly how it used the Z80, but I think it was in operation all the time.

I can't understand why the C128 didn't take off
as well as the C64. I'd guess that if it had the
same hardware restrictions as the C64, then it
wouldn't be a nice choice of a business
machine.

Yeah, I don't understand that either. The 128 is a very nice machine. Mebbe it was just too expensive to sell well?

One of the advantages of the Amstrad
CPC6128, was that it did have that 80x25 screen
& was used on many occasions for serious
software. Games wise, there were a lot of games
which used the extra 64k (because of the
CPC464/CPC664 users). The 6128 is inbetween a
PCW & a CPC because it's capable of running
CP/M (found on the PCW, the 80x25 display), but
it didn't have 256k (like the PCW base model had,
nor did it boot up CP/M the minute you switched
on the Computer) which is why it's a CPC! ;-)

I'm not real familliar with the Amstrad machines. The only one I have any experience with is the PCW. (We don't see many of the other models over here in the States.) I always thought the PCW was a very nice CP/M machine, but a lousy word processor. (I never cared for LocoScript). I have had both the 256K and the 512K (with double-sided drives) machines. If not for them, I might not have ever experienced CP/M+. (Well, that's not quite true, my PMC MicroMate ran v. 3 too.)

Commodore I've noticed brought out a series of
Business type machines, so I guess that if the
C128 was compatable with them, then I guess
that was the idea.

The original PET-type machines came in two different versions, didn't they? There were machines badged as PET (Personal Electronic Transactor), which were aimed at the home computer market, and then there was a similar line, badged as CBM, (Commadore Business Machines) which was targeted for the business market.

To businesses which might of had a PCW, would
have found a CPC6128 a nice machine for the
home, because the Disks were the same 3" &
basically the format was too.

I think the 3" drive may have been what killed off the whole line. 3" drives just never caught on in a very big way.

The PCW also had
games as well & while they were compatable on
the CPC6128, they weren't compatable with the
other CPCs with 64k (though even after
expanding a 64k Amstrad to 128k - there were
issues with CP/M Plus running on it - CP/M Plus
was what PCWs & CPC6128 could run! 8-)

Cheers,
CP/M User.

I did have a couple of games (with graphics) that ran on the PCWs. Never played with them much tho (I'm not much of a gamer).

--T

 

[CP/M User]

"Terry Yager" wrote:

> The Commodore 64 used the VIC chip in a
> similar way when running the Z80, to handle
> the display and other I/O. (The VIC is a
> kind of processor itself, isn't it?)

I'm not sure. All I've read about CPUs is they
have to address other hardware so that they
know what to do. It's supposed to be this which
makes a difference when there's another
processor cause they are supposed to work in
conjunction (sounds kinda like Multiprocessing
which I guess is what you could call it, if you
have two processors with each of them doing
two seperate things).

> Just to bring the thread back on topic, (this
> is the Tandy forum, right?) The TRS-80
> Model 16 had dual processors, it's native
> mode Z80, and an optional 68000.

I could be wrong, though my book states that
this machine comes with this dual processor.
Usually it would say if one of the processors
was an option, however in this case, it doesn't.

> When the Z80 was in control, the 68000 was
> switched out, but when in 68000 mode, it
> used the Z80 as an I/O processor, to speed
> things up. The 68000 could address more
> memory than the Z80, so the Z80 would not
> use all the machines resources. (The Mod
> 16 could take up to 1Mb, iirc). Another
> machine I used to have, the Altos 686, was
> an 80286 based machine which also used a
> Z80 for I/O. (It also had 3 Z80 DART chips,
> giving it up to 6 serial ports). I'm not sure
> exactly how it used the Z80, but I think it
> was in operation all the time.

You could be right about this, the 68000 is a
much more powerful processor than the Z80,
though some may think that if the 68000 is
powerful enough, then why put a Z80 in there
to assist it!

I can't say for sure how much memory the
68000 allowed, though the Apple Lisa
certainally had 1 Mb & uses a 68000
processor. At the time of publication, the
book stated the TRS-80 Model 16 allowed
up to 512k, though it seems like the sort
of machine, which would easily allowed
more.

> Yeah, I don't understand that either.
> The 128 is a very nice machine. Mebbe
> it was just too expensive to sell well?

Could well be, or it didn't give the support
for the Commodore business machines as
a potential home computer.

> I'm not real familliar with the Amstrad
> machines. The only one I have any
> experience with is the PCW. (We don't
> see many of the other models over here
> in the States.) I always thought the PCW
> was a very nice CP/M machine, but a
> lousy word processor. (I never cared
> for LocoScript).

I've never tried LocoScript, however on the
CPCs there was Protext, which is one of the
best word processors I've seen for this
machine. It was available on ROM, CP/M &
Amsdos. The CP/M version perhaps would
have worked with PCWs & IIRC it required
128k on the 6128.

> I have had both the 256K and the 512K
> (with double-sided drives) machines. If
> not for them, I might not have ever
> experienced CP/M+. (Well, that's not
> quite true, my PMC MicroMate ran v. 3
> too.)

> The original PET-type machines came in
> two different versions, didn't they?
> There were machines badged as PET
> (Personal Electronic Transactor), which
> were aimed at the home computer
> market, and then there was a similar
> line, badged as CBM, (Commadore
> Business Machines) which was targeted
> for the business market.

The Commodore CBM machines AFAIK
came in two models, the 4000 series &
the 8000 series. There's also this other
machine (which came in two machines)
in the form of the B (700) & P (500)
machines. This had a 6509 processor &
was compatable with the 6502. This
certainally more of the business based
machine.

> I think the 3" drive may have been
> what killed off the whole line. 3" drives
> just never caught on in a very big way.

I would say that they did well with the 3"
drive & disk (even though it never caught
on with other machines). The amount of
support for Disk drive belts & 3" Disks
was outstanding. Durability wise they were
just as good as a 3.5" disk.


> I did have a couple of games (with
> graphics) that ran on the PCWs. Never
> played with them much tho (I'm not
> much of a gamer).

I didn't see too many action games either,
more graphical based adventure games.
However, I have noticed that some arcade
games were written for it!

Cheers,
CP/M User.

 

[Terry Yager]

"Terry Yager" wrote:

> Just to bring the thread back on topic, (this
> is the Tandy forum, right?) The TRS-80
> Model 16 had dual processors, it's native
> mode Z80, and an optional 68000.

I could be wrong, though my book states that
this machine comes with this dual processor.
Usually it would say if one of the processors
was an option, however in this case, it doesn't.

I don't know if all Mod 16s came equipped with the 68K or not, but it was certainly "optional" in the sense that the machine didn't require it to function. The 68K came on a board that plugged into the Mod 16's (proprietary) expansion bus. The same bus was also used in the Models 2, and 12, but the 68K board would not work in those machines. However, back to the 16, the 68K board can be removed completely from the machine, and it will still work as a Z80-based machine. (It just won't run Xenix without it.)
The Z80, otoh, was in-built on the mainboard and couldn't be removed. I'm pretty sure the Model 6000 (successor to the 16) came with the 68000 as standard, tho.

Interesting side note: I remember reading somewhere that when Tandy announced that they were discontinuing the 16/6000 line, that thier biggest (corporate) customer was AT&T, who used them because the Xenix interfaced so well with thier mainframes running (of course) Unix. When Tandy jerked the rug from under them, they had to look around for another solution.

> When the Z80 was in control, the 68000 was
>switched-out,

You could be right about this, the 68000 is a
much more powerful processor than the Z80,
though some may think that if the 68000 is
powerful enough, then why put a Z80 in there
to assist it!

Well, to off-load some of the menial chores, allowing the 68000 to dedicate its processing power to the "real" work (number crunching, etc.). That and the simultaneous I/O would speed up any machine.
The 16 was primarily a Z80 machine, with the 68000 kinda stuck on almost as an afterthought. This was in the days when a Z80-based machine made more sense (especially one with 8" drives). CP/M was the best-selling software in the world, and the application base for it numbered in the thousands of programs, both commercial and PD. At one point the PD software base was estimated at over 5000 programs, all absolutely free. Then too, there was Tandy's own product, TRSDOS, which also ran on the Z80. (Xenix, OTOH, was just the "new kid on the block" back then).

I can't say for sure how much memory the
68000 allowed, though the Apple Lisa
certainally had 1 Mb & uses a 68000
processor. At the time of publication, the
book stated the TRS-80 Model 16 allowed
up to 512k, though it seems like the sort
of machine, which would easily allowed
more.

Hmmmn...mebbe it was the 16B that could take up to a meg. of ram (or was it 2 megs?). IIRC, the 16 (or 16B) came with a base memory of 512K, with an open expansion slot, leaving room for another mem. board. I also think that 512K was the minimum required for Xenix, but ICBW. I know that my Model 16B had 1Mb installed, I just don't recall if that was the max or not.

> I always thought the PCW
> was a very nice CP/M machine, but a
> lousy word processor. (I never cared
> for LocoScript).

I've never tried LocoScript, however on the
CPCs there was Protext, which is one of the
best word processors I've seen for this
machine. It was available on ROM, CP/M &
Amsdos. The CP/M version perhaps would
have worked with PCWs & IIRC it required
128k on the 6128.

I've never heard of that one...

The Commodore CBM machines AFAIK
came in two models, the 4000 series &
the 8000 series. There's also this other
machine (which came in two machines)
in the form of the B (700) & P (500)
machines. This had a 6509 processor &
was compatable with the 6502. This
certainally more of the business based
machine.

Again, I'm not that familliar with C= machines.

I didn't see too many action games either,
more graphical based adventure games.
However, I have noticed that some arcade
games were written for it!

Yeah, well I just thought it was neat that a CP/M machine even *had* graphics.

Cheers,
CP/M User.

--T

 

[CP/M User]

"Terry Yager" wrote:

> I don't know if all Mod 16s came equipped
> with the 68K or not, but it was certainly
> "optional" in the sense that the machine
> didn't require it to function. The 68K
> came on a board that plugged into the
> Mod 16's (proprietary) expansion bus.
> The same bus was also used in the Models
> 2, and 12, but the 68K board would not
> work in those machines. However, back to
> the 16, the 68K board can be removed
> completely from the machine, and it will
> still work as a Z80-based machine. (It just
> won't run Xenix without it.)
> The Z80, otoh, was in-built on the
> mainboard and couldn't be removed. I'm
> pretty sure the Model 6000 (successor to
> the 16) came with the 68000 as standard,
> tho.

Oh well, I was just going by a book for the
Model 16, which doesn't go into any detail
about the 68000 processor being an option.
It just states that there's one for it!

> Interesting side note: I remember
> reading somewhere that when Tandy
> announced that they were discontinuing
> the 16/6000 line, that thier biggest
> (corporate) customer was AT&T, who
> used them because the Xenix interfaced
> so well with thier mainframes running (of
> course) Unix. When Tandy jerked the
> rug from under them, they had to look
> around for another solution.

So it's a mystery rapped in a riddle!

>> I can't say for sure how much memory the
>> 68000 allowed, though the Apple Lisa
>> certainally had 1 Mb & uses a 68000
>> processor. At the time of publication, the
>> book stated the TRS-80 Model 16 allowed
>> up to 512k, though it seems like the sort
>> of machine, which would easily allowed
>> more.

> Hmmmn...mebbe it was the 16B that could
> take up to a meg. of ram (or was it 2
> megs?). IIRC, the 16 (or 16B) came with
> a base memory of 512K, with an open
> expansion slot, leaving room for another
> mem. board. I also think that 512K was the
> minimum required for Xenix, but ICBW. I
> know that my Model 16B had 1Mb installed,
> I just don't recall if that was the max or not.

I'm not sure, though I thought I read
somewhere that perhaps the Model 16 could
take up to 768k, some other 68000 based
machines were expanable to this, though I'm
going from some ol' book!


>> I've never tried LocoScript, however on the
>> CPCs there was Protext, which is one of the
>> best word processors I've seen for this
>> machine. It was available on ROM, CP/M &
>> Amsdos. The CP/M version perhaps would
>> have worked with PCWs & IIRC it required
>> 128k on the 6128.

> I've never heard of that one...

Don't know if Protext made it to the IBMs (I
know Wordstar did). Protext was written by a
company called Arnor (I believe).

>> The Commodore CBM machines AFAIK
>> came in two models, the 4000 series &
>> the 8000 series. There's also this other
>> machine (which came in two machines)
>> in the form of the B (700) & P (500)
>> machines. This had a 6509 processor &
>> was compatable with the 6502. This
>> certainally more of the business based
>> machine.

> Again, I'm not that familliar with C=
> machines.

Oh I thought you were.

Need to pay a visit to
http://www.old-computers.com/museum ??

>> I didn't see too many action games either,
>> more graphical based adventure games.
>> However, I have noticed that some arcade
>> games were written for it!

> Yeah, well I just thought it was neat that a
> CP/M machine even *had* graphics.

Well most of those games used standard
drivers, so they could work on PCWs & CPCs,
even though there's a bit of fun to be had to
play around with the system specifics (even
though it's not user friendly between those
machines - which is rather unfortunately, I
guess it's time to look at PCW specifics!).

Cheers,
CP/M User.

 

[carlsson]

I think that in the 128 however, the two processors worked in unison.

Nope, when one is running/using the bus, the other is idle even in the 128. Actually the 128 boots up with the Z80, but if no CP/M disk is found, it switches to 8510 (6510/6502 replacement). It is possible that an external Z80 with its own memory bus could run independently, but then one could have random CP/M computer on the desk next to the random 6502 computer.

VIC and SID are custom chips (call them logic arrays if you want), but hardly not worth to call central processing units. Btw, the old CBM series were 3000 and 8000 IIRC.

Regarding toys or not; I think it boils down to three things:

1. If there is software available to do something else than word processing and book-keeping, it has a toy warning
2. If it is sold too cheap, so companies can't write off big investments over three years of time, it has a big toy warning
3. If it isn't compatible with the leading product on the market, it is definitely a toy (which kind of makes both Macs and Linux PCs toys today)

 

[CP/M User]

"carlsson" wrote:

> VIC and SID are custom chips (call them logic
> arrays if you want), but hardly not worth to
> call central processing units. Btw, the old CBM
> series were 3000 and 8000 IIRC.

The book I've got clearly has 4000 & 8000 series,
in the 4000 there's the 4016 (with 16k of memory)
& the 4032 (with 32k of memory). I could be
possible though that in Europe it had a different
name or model number (from the US counterpart),
though I can't see why they would change it.

> Regarding toys or not; I think it boils down to
> three things:

> 1. If there is software available to do "something
> else" than word processing and book-keeping, it
> has a toy warning

> 2. If it is sold too cheap, so companies can't write
> off big investments over three years of time, it has
> a big toy warning

> 3. If it isn't compatible with the leading product on
> the market, it is definitely a toy (which kind of
> makes both Macs and Linux PCs toys today)

But that just states that anything which isn't IBM
compatable with a copy of Microsoft's latest crap
is a toy.

CP/M User.

 

[Terry Yager]

The book I've got clearly has 4000 & 8000 series,
in the 4000 there's the 4016 (with 16k of memory)
& the 4032 (with 32k of memory). I could be
possible though that in Europe it had a different
name or model number (from the US counterpart),
though I can't see why they would change it.

I really don't remember which it is. I have only had a few of that type of machine pass thru my hands, but they were all badged as CBM, not PET. The two were similar, but the keyboards were different, (different set of graphics characters) with the CBM machines being supplied with "Business Graphics" keyboards, or some such.

> Regarding toys or not; I think it boils down to
> three things:

> 1. If there is software available to do "something
> else" than word processing and book-keeping, it
> has a toy warning

> 2. If it is sold too cheap, so companies can't write
> off big investments over three years of time, it has
> a big toy warning

> 3. If it isn't compatible with the leading product on
> the market, it is definitely a toy (which kind of
> makes both Macs and Linux PCs toys today)

But that just states that anything which isn't IBM
compatable with a copy of Microsoft's latest crap
is a toy.

CP/M User.[/quote]

I dunno, the only computers I consider "real" computers are CP/M machines...everything else is just a toy to me (coz I like to play with them). Even machines that are clearly superior in some way.

--T

 

[Terry Yager]

I think that in the 128 however, the two processors worked in unison.

Nope, when one is running/using the bus, the other is idle even in the 128. Actually the 128 boots up with the Z80, but if no CP/M disk is found, it switches to 8510 (6510/6502 replacement). It is possible that an external Z80 with its own memory bus could run independently, but then one could have random CP/M computer on the desk next to the random 6502 computer.

Thanks, carlsson, fr coming to my rescue here. I was hoping someone would. I knew I was going way out on a limb talking about C= computers, which are really outside my realm of expertise.

VIC and SID are custom chips (call them logic arrays if you want), but hardly not worth to call central processing units. Btw, the old CBM series were 3000 and 8000 IIRC.

Oh, is that all? I was under the impression that the VIC chip was a "graphics processor" (not a general-purpose CPU), kinda like the "graphics accelerators" found in modern video cards, which do have some processing ability. Similarly, the SID chip is an "I/O processor", isn't it? This could still be accomplished on a gate-array chip. (Please enlighten us if I am wrong about this, I'd love a clearer explaination).


--T

 

[Unknown_K]

I always thaught anything you can write a program and execute it was a computer. Being able to play a game doesnt make it a toy.

My old Radioshack PC-6 "Pocket Scientific Computer" is as small as a caculator and only have a small one line LCD display but was great for programming complex equations where you entered your input and it gave you answers. It had some sort of basic also.

 

[carlsson]

I was under the impression that the VIC chip was a "graphics processor" (not a general-purpose CPU), kinda like the "graphics accelerators" found in modern video cards, which do have some processing ability.

No. The GTIA on the Atari might be called a graphics processor, as you can create copper lists of operations to be run in an order IIUIC. The VIC-II will draw an image, and you can take advantage of its bugs to extend the capabilities beyond what it was supposed to do, but I still would not call it graphics processor, since it needs the graphic data to show ready made (either from ROM or RAM).

The fact that these custom chips are complicated in how they work, in particular when bugs are exposed, makes it very hard to emulate them, much harder than a well-documented CPU. The SID filters in particular is a mystery, which also worked slightly different from unit to unit.

 

[Terry Yager]

I was under the impression that the VIC chip was a "graphics processor" (not a general-purpose CPU), kinda like the "graphics accelerators" found in modern video cards, which do have some processing ability.

No. The GTIA on the Atari might be called a graphics processor, as you can create copper lists of operations to be run in an order IIUIC. The VIC-II will draw an image, and you can take advantage of its bugs to extend the capabilities beyond what it was supposed to do, but I still would not call it graphics processor, since it needs the graphic data to show ready made (either from ROM or RAM).

The fact that these custom chips are complicated in how they work, in particular when bugs are exposed, makes it very hard to emulate them, much harder than a well-documented CPU. The SID filters in particular is a mystery, which also worked slightly different from unit to unit.

Oh, ok...thanks for clearing that up.
BTW, my Cambridge Z88 is a four chip machine. Inside it you'll find a cmos Z80 processor, a RAM chip, a ROM chip, and one honkin' big custom gate array that does everything else. Kinda kewl how they cn build a whole computer on one single chip, eh?

--T

 

[Terry Yager]

I always thaught anything you can write a program and execute it was a computer. Being able to play a game doesnt make it a toy.

My old Radioshack PC-6 "Pocket Scientific Computer" is as small as a caculator and only have a small one line LCD display but was great for programming complex equations where you entered your input and it gave you answers. It had some sort of basic also.

I guess the kiddies today have a whole different notion of what is or is not a "computer" than what we old-school hackers have. Like my own kid teasing me about using my Tandy 102, calling it an "overgrown pocket calculator", just because modern calculators are probably "smarter" than the 102. I do love those old Tandy portables, especially the hand-helds like the PC-6 (never had one...yet).

--T

 

[Terry Yager]

Yes, I cannot explain how the Z80 worked with
the C64. However, in one of my books it
explains that for machines which can have
another processor available for this, then the
both of them can work together. The computer
they were giving an example which did this, is
one (if not all) of the BBC based computers
which is 6502 based, but can have a Z80
plugged into it. They stated that a program
written using Z80 would use the Z80 processor,
while the 6502 could concentrate on other
hardware like the display & possibly the
other resources, but that the 6502 processor
would have been freed up.

Cheers,
CP/M User.

I was reading the BBC User's Guide last night, and turned up that (with the Z80 add-in) when running in Z80-Mode, the 6502 is used as an I/O processor, but when in 6502-Mode, the Z80 is switched out. Hmmmn, just the opposite as I would've guessed, given that the Z80 is the add-in, and not the "primary" processor.

--T

 

[carlsson]

Maybe it has something to do with the Z80 add-in knows there is a 6502 subsystem (which is connected to the I/O, so it is assigned this task), but the 6502 system is not designed with a Z80 in mind, and that there is not much tasks it could be assigned if it is not the main processor running.

 

[Terry Yager]

Maybe it has something to do with the Z80 add-in knows there is a 6502 subsystem (which is connected to the I/O, so it is assigned this task), but the 6502 system is not designed with a Z80 in mind, and that there is not much tasks it could be assigned if it is not the main processor running.

Yeah, you're probably right, carlsson. The Z80, being the (later?) add-in would be "aware" of the 6502 and be designed to work with it, whereas the opposite is not necessarily true.

--T

 

[CP/M User]

"Terry Yager" wrote:

> I was reading the BBC User's Guide last
> night, and turned up that (with the Z80
> add-in) when running in Z80-Mode, the
> 6502 is used as an I/O processor, but
> when in 6502-Mode, the Z80 is switched
> out. Hmmmn, just the opposite as I
> would've guessed, given that the Z80 is
> the add-in, and not the "primary"
> processor.

Oh okay, well in the Osborne guide to
Expanding your Micro it discussed the
same concept of the original
Microprocessor doing the Screen Display
& Keyboard & the Second processor
carries out the calculations & then sends
the results to the original processor!
(Pretty much the same as what you said!


But I didn't know about this 6502 only
mode & Z80-mode (unless the Z80 were
plugged in or out)!

Cheers,
CP/M User.