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It's alive, my Datapoint 2200/1100 !

jdreesen

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Jul 5, 2012
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Anf finally, after a few years in my possession, the machine has been restored to the point where it now enters the build-in debugger. I first had to read the Datapoint 5500 manual to understand how to enter the debugger. And now need to understand this debugger some more, existing documentation is rather shortcoming here.


dp2200_dbg.jpg

The debugger code lives in the bootrom, which is not present in the 2200, but is in the 1100. The 1100 bootboard sits in the slot occupied by the 2200 cassette reader PCB, and mimicks a booting casette. So if a DP2200 owner want to try this he will have to swap the RX board with a DP1100 boot board.

Note : in this picture the innards of the machine have been swung into the "service" position, allowing access to the PCB's with the keyboard still in place. A pin on each side holds the unit in this position.

Jos
 

jdreesen

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So next step is to boot using the floppydrives. Images (DOS.C) are available thank to Al, but does anyone have schematics for the DP9380 Quad floppy disk controller ?
This are 2 big board full of TTL, around 250 of them.( 1973, so no single chip FDC controller...)

Some mice mistook my boards for a lavatory, so there is bound to be damage..
 

Al Kossow

Documentation Wizard
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So next step is to boot using the floppydrives. Images (DOS.C) are available thank to Al, but does anyone have schematics for the DP9380 Quad floppy disk controller ?
This are 2 big board full of TTL, around 250 of them.( 1973, so no single chip FDC controller...)

Some mice mistook my boards for a lavatory, so there is bound to be damage..

the only place would be the musem in san antonio. i've not had much luck convincing Austin Roche to scan documents
https://www.thestoryoftexas.com/dis...int-computer-terminal-2200-spotlight-01-31-18
 

jdreesen

Experienced Member
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Jul 5, 2012
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408
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Switzerland
My other option for mass storage would be the Datapoint 9350 cartridge disk ( a rebadged Diablo 30 ) or the DP9360 cartridge disk .

http://www.bitsavers.org/pdf/datapoi...Data_Sheet.pdf

Anyone recognize the original disk manufacturer for the 9360 ? ( and what are my chances of finding one...)

I have a suitable DP controller with a 4K-buffer. No schematics for this of course....
 

jdreesen

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Jul 5, 2012
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Switzerland
...and this machine has now suffered a shorted mains rectifier. And it also turns out the main internal fuse was shorted....
Anyhow I had do draw up the mains schematic : here it is (220V version) ( similar in concept to the schematics in Bitsavers, but very different control electronics )
The same powersupply is also used in the Datapoint 5500. As can be seen at lot of exposed electronics is on the mains / primary side...
 

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  • DP2200_psu.pdf
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  • psu_cmp_2.jpg
    psu_cmp_2.jpg
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  • psu_cmp_1.jpg
    psu_cmp_1.jpg
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jdreesen

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Jul 5, 2012
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Switzerland
Currently reverse engineering the "RAM display logic board". This is the video board used in later versions of the 2200, and in the 5500, possibly in the 6600.
It has 2 sets of 7 each 2102's . Obviously one holds the character data, the other the font data. However I cannot see how the font data is loaded, no commands to that purpose are in the documenation, the boot program that Gordon Peterson kindly documented does not show where the font data is loaded.
It obviously works, as I was able to enter the debugger, at least until the powersupply blew....

Anyone has a hint ?
 

jdreesen

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..never mind. It is all there in the 5500 manual, and yes, a partial fonttable is in the boot program, right at the end.....
 

lucyferpl

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May 23, 2022
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Somewhere in the future
Anf finally, after a few years in my possession, the machine has been restored to the point where it now enters the build-in debugger. I first had to read the Datapoint 5500 manual to understand how to enter the debugger. And now need to understand this debugger some more, existing documentation is rather shortcoming here.


View attachment 1222198

The debugger code lives in the bootrom, which is not present in the 2200, but is in the 1100. The 1100 bootboard sits in the slot occupied by the 2200 cassette reader PCB, and mimicks a booting casette. So if a DP2200 owner want to try this he will have to swap the RX board with a DP1100 boot board.

Note : in this picture the innards of the machine have been swung into the "service" position, allowing access to the PCB's with the keyboard still in place. A pin on each side holds the unit in this position.

Jos
Do you perhaps have a copy of the contents of this ROM from the 1100?
 

jdreesen

Experienced Member
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Jul 5, 2012
Messages
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Location
Switzerland
Sure, appended here. First the disassembled bootrom, documented by Gordon Peterson. This is also on Bitsavers. The version here is updated, starting at 03643 octal, showing the partial font set at the end of ROM. This is loaded into the RAM display logic board.
I also added the straight binary dump of the ROM.

Note that this bootrom assumes the presence of the 9380 quad 8" floppy system, which very few people will have. It uses a IBM 3740 compatible disk layout.
 

Attachments

  • DisketteBootDisassemblyGEP2ft.txt
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  • DP1100DisketteBoot.bin.txt
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Last edited:

lucyferpl

Member
Joined
May 23, 2022
Messages
47
Location
Somewhere in the future
Sure, appended here. First the disassembled bootrom, documented by Gordon Peterson. This is also on Bitsavers. The version here is updated, starting at 03643 octal, showing the partial font set at the end of ROM. This is loaded into the RAM display logic board.
I also added the straight binary dump of the ROM.

Note that this bootrom assumes the presence of the 9380 quad 8" floppy system, which very few people will have. It uses a IBM 3740 compatible disk layout.
Thank you so much!
I wonder if I could take a few more moments of your attention
The topic of datapoint machines is very intriguing, and apart from the company's official materials, I have not been able to find answers to several questions
 

jdreesen

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I am of course in no way a Datapoint specialist, I just happened to be able to acquire a DP1100 cheaply. And by coincidence just now had an email from the designer of the ROM board....
But feel free to ask...
 

Al Kossow

Documentation Wizard
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Sep 1, 2006
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I am of course in no way a Datapoint specialist, I just happened to be able to acquire a DP1100 cheaply. And by coincidence just now had an email from the designer of the ROM board....
But feel free to ask...
does he have any documentation/software that hasn't been archived?
 

jdreesen

Experienced Member
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Jul 5, 2012
Messages
408
Location
Switzerland
Here is the sourcecode for CTOS, the cassette operating system for the earlier versions of the DP2200 / DP1100.
Later versions of the 2200/1100 ( and 5500) use a videocard with a programmable characterset, not supported by this early CTOS version.

It was obtained by OCR'ing and handcorrecting the listing in 2200_Programmers_manual_aug71.pdf
I should whip up a crossassembler to check this some more, but lack the time right now.

Final goal would be to create a new PCB, combing the 2200 casssette demodulator and the 1100 ROM board. This way machines with troublesome cassette systems could be made to boot...
 

Attachments

  • CTOS.asm.txt
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