I have a new VIC-20 at last!

[dongfeng]

Hi~

I'm sorry to say, my VIC is not special, I simply had the 3k memory expansion installed when I took the photo :lol:

I've got the Vixen cartridge working now too, so an extra 16k! I opened it up as per your suggestion and cleaned the contacts. I also opened up the vic again and took some pictures of the underside of the motherboard. Still no "press play" message despite cleaning the datasette up, I will bring back my original VIC's datasette at the weekend.

Regarding the VIC21, I am almost certain that was just a publicity stunt to sell the leftover VICs when they weren't selling well. They simply stuck a "Super VIC 21" sticker over the original logo on the box and stuffed an external expansion cart in the box! As so: http://www.zimmers.net/cbmpics/cvic1.html

I still don't know if this VIC is newer or older than my original. The case on the "new" vic seems to be a poorer design on the inside. I will post some pictures as soon as my friend returns my camera cable :x

I'm pretty sure my original VIC was one of the last ones ever made - commodore may have been using up old cases (hence why my UK machine has a German-spec VC20 badge). I will go and look at it next weekend.

vic user: I will scan in some of the books sometime! you might have to wait until easter when I get to use my scanner as I don't have it here maybe I can use the one at University... I will see!

thanks for the info everyone!!!

 

[Terry Yager]

Ok. To clear the confusion, I present a complete memory map.

<map snipped>

Did this confuse even more or clear any questions?

Ok, I give up. (Tired of searching the net). I bow to your clearly superior knowledge of C= hard/software. <scraping, bending, bowing> I'm not worthy, I'm not worthy, I'm not worthy...

--T

 

[carlsson]

I bow to your clearly superior knowledge of C= hard/software.

Hey, I'm sure there are other areas of this board where you know more than me. That's the point of specializing into something. The most horrendous "technical specification" I stumbled upon yesterday while searching the net was this:

Both the VIC-20 and C64 were based on the Z82 processor (err.. what is that - a combination of Z80 and 6502?). The VIC had 2 kB of memory and a 20x20 resolution (22x23), while the C64 had 40x40 (40x25). Both had sixteen colours and three channels of sound plus noise (which is pretty close to the truth). They use 5.25" floppies which can store approx 650 kB per disk (try 166 kB per disk side).

Regarding the screen shot was taken with 3K Super Expander plugged in.. I just did my homework and found out that the cartridge adds 3K but steals 136 bytes of these at startup, so the number 6519 is correct after all. Sorry, but I hadn't realized this was happening.

When you open a graphic screen, it allocates even more memory and leaves you at 3069 bytes (3K) remaining. There is a Finnish web page about the Super Expander with home-made examples if you like:

http://www.ntrautanen.fi/computers/commodore/archive/vic_super.htm

 

[vic user]

dongfeng wrote:

vic user: I will scan in some of the books sometime! you might have to wait until easter when I get to use my scanner as I don't have it here maybe I can use the one at University... I will see!

That would be super amazing! Even the table of contents before Halloween would be cool

Chris

 

[Terry Yager]

The most horrendous "technical specification" I stumbled upon yesterday while searching the net was this:

Both the VIC-20 and C64 were based on the Z82 processor (err.. what is that - a combination of Z80 and 6502?). The VIC had 2 kB of memory and a 20x20 resolution (22x23), while the C64 had 40x40 (40x25). Both had sixteen colours and three channels of sound plus noise (which is pretty close to the truth). They use 5.25" floppies which can store approx 650 kB per disk (try 166 kB per disk side).

Heh! That is a good one...I missed it somehow. Wow! 650K drives wouldn't that be nice?

Hey, thanx for the link but um, my Finnish is, uh, a little rusty. Pretty pictures, tho. Speaking of pictures, a friend of mine used to have a picture of the Windows 3.1 splash screen for his C-64. Have you ever seen that one? Kinda cute...

--T

 

[carlsson]

Well, the 5.25" drives using 96 tpi and double density should put some 500K per disk using both sides I believe - isn't that typical CP/M systems? I'm not too familiar with the different tpi rates and density vs how data is stored on different formats, but given maximum tweaking and compressing data internally it might work. Remember the 5.25" HD disks for the IBM PC stored 1.2 MB each and they're still 5.25" although with a more dense storage space.

I don't know about the splash screen in C64 mode, but I do have a modified splash screen for the Amiga which looks like the Windows 3.1 one. It has the peculiarity that it opens its own screen and you have to close it afterwards, or else it sits in the background and takes memory.

 

[Terry Yager]

Well, the 5.25" drives using 96 tpi and double density should put some 500K per disk using both sides I believe - isn't that typical CP/M systems? I'm not too familiar with the different tpi rates and density vs how data is stored on different formats, but given maximum tweaking and compressing data internally it might work. Remember the 5.25" HD disks for the IBM PC stored 1.2 MB each and they're still 5.25" although with a more dense storage space.

A 96tpi drive under CP/M would usually store up to around 800K, depending on it's formatting (bytes/sector, etc). These were known as "quad density", but they were never very common. They used regular DSDD media, no special QD disk was needed. A double-sided, double-density 8" drive would format out to 1.2Mb (assuming 1024 bytes/sector). The formating of those drives is the same as the IBM 1.2Mb 5.25" format, which makes them a suitable replacement drive for a CP/M system, once you get the cableing right. No BIOS modification is necessary when doing that swap-out.

--T

 

[carlsson]

I have at least two or three 96 tpi DSDD disks (which are Commodore formatted, so a waste of resources as the 1541 formats 35 tracks in single density). One of them is a Luxor ABC disk, which tells me that the Swedish ABC-800 system, which was Z80 based but not CP/M compatible AFAIK, also took advantage of this format.

 

[Terry Yager]

I have at least two or three 96 tpi DSDD disks (which are Commodore formatted, so a waste of resources as the 1541 formats 35 tracks in single density). One of them is a Luxor ABC disk, which tells me that the Swedish ABC-800 system, which was Z80 based but not CP/M compatible AFAIK, also took advantage of this format.

Yeah, my PMC Multi-Mate used 96tpi, under CP/M v. 3.0, at least it did until it died. I also used to use 96tpi drives with my Tandy CoCo 3, under OS9 Level II (a Unix-like operating system for 68xx-based machines). It doesn't surprise me that the C= 128 could use them also. (Did it require a 1571, or what?)

--T

 

[Terry Yager]

Warning, OT

Warning, OT

OT (non-Commodore) post:

The Victor (Sirius) 9000 used to use 96tpi drives too, IIRC. It was an MSDOS&CP/M-86 machine, but was not IBM compatable. That whole machine was a strange animal, especially the disk system. The disks were 600K for SS, and 1.2Mb for DS drives, but the formatting was very strange. They did not use fixed sector sizes. The data was packed in at the same density on the outer (longer) tracks as on the inner, but the # of bytes per sector was greater. The drives themselves were a special, variable-speed thing. The motors in them were quite loud, but I never minded. Listening to them was like music to my ears. When doing an operation that accessed the whole disk, like formatting, it kinda reminded me of a sports car winding out thru it's gears as the drive changed speeds:
hmmmmmmnn...HMMMMMMMNN...whiiiiiiinnne...WHEEEEEEEE!, then, if it was a double-sided drive, it would suddenly down-shift and start all over again going thru the "gears" because the Victor 9000 only formated one side of the disk at a time. The head-load mechanism on them was pretty loud, too. I used to love listening to them, and watching the lights blink back-and-forth when copying a disk. Looked and sounded kinda like a RR crossing's semiphore lights going off. Kerchunk, kerchunk, kerchunk! Blink, blink blink! Loved it! (The Victor 9000 also has the prettiest built-in character set I have ever seen in a computer, kind of a seriph-type font that was just a joy ot look at). I really miss my old Victors.

--T

 

[carlsson]

The C128 probably had to be as backward compatible as possible. Its native drive is the 1571, which is a double-sided drive but still formatting 35-40 tpi single density AFAIK. Besides in 1985ish, other disks like 3" and 3.5" were on their way in so it wiser to consider moving to this technology. I don't know if the CBM/PET series with their 8050 drives and what it is called are formatting QD, but I believe so.

Victor/Sirius is not as off-topic as you might think. Datatronic, the Swedish agent for Commodore Business Machines, at least partially bought Victor/Sirius and for a short while offered both brands to their resellers. Commodore themselves later opened their own local office and took over the Commodore computers completely. I even believe Chuck Peddle of 6502 fame was deeply involved in constructing the Victor machine, but I would have to look up that.

 

[Terry Yager]

The C128 probably had to be as backward compatible as possible. Its native drive is the 1571, which is a double-sided drive but still formatting 35-40 tpi single density AFAIK. Besides in 1985ish, other disks like 3" and 3.5" were on their way in so it wiser to consider moving to this technology. I don't know if the CBM/PET series with their 8050 drives and what it is called are formatting QD, but I believe so.

I'm not sure what disk format the PET used.

Victor/Sirius is not as off-topic as you might think. Datatronic, the Swedish agent for Commodore Business Machines, at least partially bought Victor/Sirius and for a short while offered both brands to their resellers. Commodore themselves later opened their own local office and took over the Commodore computers completely. I even believe Chuck Peddle of 6502 fame was deeply involved in constructing the Victor machine, but I would have to look up that.

I didn't know that Commodore had anything to do with Victor/Sirius. Thanks for pointing that out. Yeah, Chuck Peddle designed both the Pet and the Victor 9000. Old.computers.com has a pretty good write-up:

http://www.old-computers.com/museum/computer.asp?st=1&c=210

Documentation for Victor/Sirius machines is very rare to find these days. Sometimes the docs are more valuable that the machines themselves. This is because they didn't come supplied with any documentation. The docs were only distributed to the dealers, on the theory that the dealer should set the customer up with all the hardware & software they would need, and the computer should be so easy to use that documentation was unnecessary. If you ever run across any docs, grab them up...very collectable.

--T

 

[carlsson]

The PET series used an IEEE-488 interface, and the following drives seem to have existed or were planned but never released:

2031/2041/4031 = 1x 5.25", 35 tpi, 170 kB single sided
2040/3040/4040 = 2x 5.25", 35 tpi, 170 kB single sided
SFD1001 = 1x 5.25", 77 tpi, 1 MB double sided
8050 = 2x 5.25", 77 tpi, 512 kB single sided
8061 = 2x 5.25", unknown capacity
8250 = 2x 5.25", 77 tpi, 1.05 MB double sided
8060 = 2x 8", 750 kB
8280 = 2x 8", unknown capacity

Compare to the IEC (serial) and later drives:

1540/1541/1542/1551/1570/SFS841 = 1x 5.25", 35 tpi, 170 kB single sided
1571 = 1x 5.25", 35 tpi, 340 kB double sided
1572 = 2x 5.25", 35 tpi, 340 kB double sided
1581 = 1x 3.5", 80 tpi, 800 kB
1563 = 1x 3.5", unknown capacity

Regarding Victor and Commodore; it was the local agent/distributor who acquired some of it, not the mother company (AFAIK).

 

[Terry Yager]

The PET series used an IEEE-488 interface,

Ah,yes. The ever popular "gibb" socket. (Ever wonder why it's pronounced "gibb" even though it's spelled HP-IB?)

Regarding Victor and Commodore; it was the local agent/distributor who acquired some of it, not the mother company (AFAIK).

But still, the Chuck Peddle connection is significant...

--T

 

[barryp]

Ever wonder why it's pronounced "gibb" even though it's spelled HP-IB

IIRC, it's also GPIB - General Purpose Instrument Bus.

Confirmation anyone?

 

[Terry Yager]

Ever wonder why it's pronounced "gibb" even though it's spelled HP-IB

IIRC, it's also GPIB - General Purpose Instrument Bus.

Confirmation anyone?

Close, (I googled it):

General Purpose Interface bus, also known as HP-IB. The standard bus used for controlling electronic instruments with a computer. Also called IEEE 488 bus because it is defined by ANSI/IEEE Standards 488-1978, and 488.2-1987.
www.allaboutmems.com/glossary.html

Thanks, I don't recall ever hearing that translation before.

--T

 

[barryp]

Close, (I googled it):

General Purpose Interface bus

I always seem to forget the ultimate cofirmation, but of course when I go on Jeopardy I'll be on my own @;^}

I guessed Instrument since that's what (I think) its main use is.

 

[Terry Yager]

Close, (I googled it):

General Purpose Interface bus

I always seem to forget the ultimate cofirmation, but of course when I go on Jeopardy I'll be on my own @;^}

I guessed Instrument since that's what (I think) its main use is.

"Instrument" sounds like a very good guess to me. Did H-P actually invent the bus, which was subsequently "standardized" by the IEEE, or what? (I do remember that HP-IL stands for Hewlett Packard Interface Loop. Does it have an IEEE spec too?)

--T