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National Semiconductor SC/MP Low Cost Development System Manual Needed

GeoffC

Member
Joined
Aug 26, 2018
Messages
20
Howdy,

It's my first post here. I've been hunting for one of these systems for a long time - it was my first computer ever and was lost to the ravages of a mom on a cleaning rampage many years ago .. I'm sure some here can sympathize!

I found one at VCF West and snapped it up!

Here's a link to a page showing such a system:

https://collections.museumvictoria.com.au/items/393735

(Note I'm in California, USA not Australia - they just have some pages about the LCDS).

I found It seems to work! I have some documentation but I'm missing the main manual for the system - pictured here:

https://collections.museumvictoria.com.au/items/1136671

I contacted the museum for a possible copy of the manual but no dice so far.

Does anyone have a manual they'd part with or make a scan of? Of course I'd be willing to pay a reasonable amount for either.

Thanks for looking.

Geoff
 

river

Member
Joined
Jan 4, 2015
Messages
36
Location
Sydney, Australia
Hi,

Yes, I have the manual. It's a part of my SC/MP LCDS, but mine isn't working so I am currently fixing it. Originally the system came with a bunch of manuals, including the system manual, datasheets, circuit diagrams and the EPROM listings. It's not a small manual and, being old, it is fragile and the spine is breaking. It will be a while before I would be able to get it fully scanned.
 

inotarobot

Veteran Member
Joined
Feb 7, 2014
Messages
1,090
Location
Melbourne, Australia
Howdy,

It's my first post here. I've been hunting for one of these systems for a long time - it was my first computer ever and was lost to the ravages of a mom on a cleaning rampage many years ago .. I'm sure some here can sympathize!

I found one at VCF West and snapped it up!

Here's a link to a page showing such a system:

https://collections.museumvictoria.com.au/items/393735

(Note I'm in California, USA not Australia - they just have some pages about the LCDS).

I found It seems to work! I have some documentation but I'm missing the main manual for the system - pictured here:

https://collections.museumvictoria.com.au/items/1136671

I contacted the museum for a possible copy of the manual but no dice so far.

Does anyone have a manual they'd part with or make a scan of? Of course I'd be willing to pay a reasonable amount for either.

Thanks for looking.

Geoff

Hi Geoff,

If you have no joy, since I live in Melbourne Australia, I will contact museum and ask can I see and photograph manual.

Will let you know.

regards
David
 

GeoffC

Member
Joined
Aug 26, 2018
Messages
20
Hi - thanks for replying!

river I understand about scanning the document taking a while.
Do you know what's wrong with your LCDS? Let me know if there is anything I can check on mine that might help you.

David thanks for the offer of checking the museum!

Geoff
 

GeoffC

Member
Joined
Aug 26, 2018
Messages
20
Hello river and David

river I understand about the manual scanning being tricky!
If there is anything I can check on my LCDS to help you with yours please let me know!
A question about the manual - does it have the schematic for the CPU card? If so a scan of just that would be very helpful!

David thanks for your offer! Have you been to that museum before? We have a good computer history museum here in California that I've been to a few times.

Geoff
 

inotarobot

Veteran Member
Joined
Feb 7, 2014
Messages
1,090
Location
Melbourne, Australia
Hello river and David

river I understand about the manual scanning being tricky!
If there is anything I can check on my LCDS to help you with yours please let me know!
A question about the manual - does it have the schematic for the CPU card? If so a scan of just that would be very helpful!

David thanks for your offer! Have you been to that museum before? We have a good computer history museum here in California that I've been to a few times.

Geoff

Hi Geoff and river,

Geoff I have just phoned the MuseumVictoria and asked for access to the documentation, and also possibly the Hardware. Currently, it is in offsite storage so I have to wait for the request to be processed though their system.

I think it's likely you would get a copy from river quicker.

river I suggest the simplest way is to get a hold of a digital camera or mobile(cell) Phone camera and just take some pics of the CPU drawing for now.

Upload them to imgur.com, that free, then post the image link/s here. That's way easier than scanning for now whole manual or even the cct drws. When I do this way as temp way, I take a wide pic of full drawing and depending on camera resolution I will mentally divide drawing and take say 4 closer pics of the image giving a small bit of overlap
 

river

Member
Joined
Jan 4, 2015
Messages
36
Location
Sydney, Australia
Hi,

No, I don't know what it's issue is at the moment. I think it could be the ROMs but these are some weird NS chips and do not follow the standard pinouts, so I will plug them into my 8085 Dev system where I have access to the 8085 system bus and a spare chip select, and it has a built in breadboard.... so will connect them up one at a time and check if the code in them is fine, by comparing to the listings from the LCDS Manual. I have also typed in the LCDS code, via the listings, and x-assembled it and verified it is 100% same as the original. I will burn a 2732 to hold all the code and hook this up via one of the J connectors and mount it in the chassis.

I have seen those CPU testers about, but I have systems that take most of the old CPUs, so I just use one of those systems to validate if a CPU from my parts drawers is operational or not. In regards to SC/MP CPU, I have a few SC/MP I and SC/MP II CPU and I am currently writing a debug/monitor for a homebrew SC/MP system I designed/built. I have one more week before I am on vacation from work (until mid Jan) and will get some pics/images for you from the LCDS manual.
 

realtime

New Member
Joined
Dec 10, 2018
Messages
3
Location
Melbourne, Australia
I am new to this forum, and hope some of you can help me with the restoration of an LCDS I have just acquired (ex. ebay) which appears to have been listed by a family clearing out someones collection. Fortunately the recognised that it was a significant piece of history. It comes with 2 memory cards and 2 cpu cards, plus a SC/MP kit with KITBUG rom.

But it does not have an original set of roms on the LCDS board, and first powerup shows no life in the display or keyboard. So either, the replacement EPROMS are now erased, or they have totally different code in them.

So I am going to see if I can get the KITBUG rom and one of the CPU cards operating on the LCDS, so I can you use it to interrogate and exercise the the unit. Hopefully this will allow me to examine the ROMS and test the display and keyboard.

But of particular interest to this thread, I contacted Museums Victoria, and they have supplied me with a complete PDF of the LCDS manual!!

So I am hoping that someone here who has a working system could supply a complete hex listing of the original ROMS, and I would be happy to share the manual.
 

inotarobot

Veteran Member
Joined
Feb 7, 2014
Messages
1,090
Location
Melbourne, Australia
Howdy,

It's my first post here. I've been hunting for one of these systems for a long time - it was my first computer ever and was lost to the ravages of a mom on a cleaning rampage many years ago .. I'm sure some here can sympathize!

Geoff

I assume she had planned a Left Accumulator Shift of it into a cupboard but got a NOP so actually actually deleted it POST haste.
 

GeoffC

Member
Joined
Aug 26, 2018
Messages
20
Hi Everybody,

Sorry I haven't been keeping up with this thread.

Museum Victoria also sent me a PDF of the manual - very nice to have! They must have been very surprised at the sudden burst of interest!! :D

If anyone wants me to check something out on my working system just let me know!
I did dump the ROMs but it sounds like folks have access to listings etc.

Geoff
 

river

Member
Joined
Jan 4, 2015
Messages
36
Location
Sydney, Australia
Hi,

Unfortunately the actual SC/MP LCDS Manual isn't in the Bitsavers repository.

I am currently restoring an LCDS, but it fortunately has all the manuals. I was able to read the ROMs using my homebrew 8085 system, but one of the ROMs is dead. I hand typed the LCDS listing and ran it through my 2650 x-assembler, and then cross checked it to ensure the x-assembler output perfectly matched the LCDS listing. I burnt it to a 2716 EPROM and connected it up via the standard LCDS bus, but it didn't work. Maybe it needs to be burnt into 4 x 2716 EPROMS, using only 512bytes of each ROM and connected to the signals that connected the original ROMs. So, I will give that a try when I get a chance.
 

Al Kossow

Documentation Wizard
Joined
Sep 1, 2006
Messages
3,454
Location
Silicon Valley
Hi,

Unfortunately the actual SC/MP LCDS Manual isn't in the Bitsavers repository.

I am currently restoring an LCDS, but it fortunately has all the manuals.

do you have a way to make a copy of the manuals, or scan them?
I know someone who has a partial LCDS and would like to put together the missing pieces
 

SiriusHardware

Veteran Member
Joined
Feb 15, 2014
Messages
805
Location
UK
Maybe it needs to be burnt into 4 x 2716 EPROMS, using only 512bytes of each ROM and connected to the signals that connected the original ROMs.
So, I will give that a try when I get a chance.

If you are saying that the PROM code was originally programmed into multiple PROM devices (of which one failed) then you should be able to use a single EPROM programmed only with the code that PROM originally contained to substitute for that device.

Just make sure the /CE signal on the PROM's socket is connected to both the /CE ( pin 18 ) and /OE ( pin 20 ) pins of the substitute EPROM, and make sure all unused lines of the EPROM, especially the upper address lines, are tied to an appropriate state (So if the original PROM only has A0-A8, say, tie A9, A10 on the 2716 EPROM to 0V).

If the original PROM is 4-bit wide, then obviously only connect D0-D3 of the 2716 to the corresponding pins on the socket.

Also, VPP (pin 21) on a 2716 needs to be held at +5V in read mode.

When doing this kind of thing I usually take a surplus ordinary (not turned pin) socket which will fit into the socket for the PROM and then solder wires to the contacts of the surplus socket. These wires I then take to the corresponding pins of a larger socket which is the right size for the EPROM which will be standing in for the PROM.

Attached, an example of this sort of adaptor lashed up to make a standard 8-bit wide EEPROM look like two 4-bit wide bipolar PROMs. The image clearly shows that the makeshift 'headers' for plugging into the 16-pin PROM sockets are just IC sockets with wires soldered to them. I use ordinary sockets rather than turned-pin because their flat pins fit more snugly into existing conventional sockets than the round pins of turned-pin sockets do.
 

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