Slot | Chip | MAKS label |
1 | ||
2 | ||
3 | AM9218BCC | 2641-4904 |
4 | CN7640F | 2641-4912 |
5 | AM9218BCC | 2641-9465 |
6 | CN7214 | 2639-6838 |
7 | CN7215F | 2639-6853 |
8 | CN7216F | 2639-6861 |
9 | ||
10 | ||
11 | CN7217F | 2639-6879 |
12 | CN7642F | 2641-4938 |
13 | AM9218BCC | 2641-4946 |
14 | C48143 | 2641-4953 |
15 | C48144 | 2641-4961 |
16 | CN7792F | 2641-4979 |
Hello,As it happens I acquired one of these terminals yesterday, a TD833 with a REV D CPU board. My initial attempts to dump the ROMs were unsuccessful however I understand where I went wrong and am in the process of making an adaptor so I can read the AM9218s as a 27128, effectively mapping the three CS pins to A11, A12, and A13.
The way the ROMs are generally wired can be seen in the image below.
View attachment 1258464
The address lines and CS lines are common to all ROMs
The 16 ROMs are in two groups of 8 each with a data bus each, a bus is selected via the CPU using some N8T97N (tri-state).
I don't know where the CS lines are derived, however, they can't be directly mapped from the address bus as there is insufficient address space.
Incidentally, it would happen that my power supply is also not working, any load on the 5V rail, and the power supply shutdowns. Cliff if you could possibly provide me with a list of voltages and their location I would appreciate that greatly. I have seen 5v 20v -21V however I don't know if there are more. One of the 5v regulators looks to be shorted to ground too, or perhaps it's just off.
Here is a table of the ROMs this system has.
Slot Chip MAKS label 1 2 3 AM9218BCC 2641-4904 4 CN7640F 2641-4912 5 AM9218BCC 2641-9465 6 CN7214 2639-6838 7 CN7215F 2639-6853 8 CN7216F 2639-6861 9 10 11 CN7217F 2639-6879 12 CN7642F 2641-4938 13 AM9218BCC 2641-4946 14 C48143 2641-4953 15 C48144 2641-4961 16 CN7792F 2641-4979
Here is a link to some of the information have gathered
Burroughs TD833 - Google Drive
drive.google.com
BTW I noticed that the ROMS 5V power rail is also seperated (they do not share the same 5V power rail, it is connected to IC SSD1927).As it happens I acquired one of these terminals yesterday, a TD833 with a REV D CPU board. My initial attempts to dump the ROMs were unsuccessful however I understand where I went wrong and am in the process of making an adaptor so I can read the AM9218s as a 27128, effectively mapping the three CS pins to A11, A12, and A13.
The way the ROMs are generally wired can be seen in the image below.
View attachment 1258464
The address lines and CS lines are common to all ROMs
The 16 ROMs are in two groups of 8 each with a data bus each, a bus is selected via the CPU using some N8T97N (tri-state).
I don't know where the CS lines are derived, however, they can't be directly mapped from the address bus as there is insufficient address space.
Incidentally, it would happen that my power supply is also not working, any load on the 5V rail, and the power supply shutdowns. Cliff if you could possibly provide me with a list of voltages and their location I would appreciate that greatly. I have seen 5v 20v -21V however I don't know if there are more. One of the 5v regulators looks to be shorted to ground too, or perhaps it's just off.
Here is a table of the ROMs this system has.
Slot Chip MAKS label 1 2 3 AM9218BCC 2641-4904 4 CN7640F 2641-4912 5 AM9218BCC 2641-9465 6 CN7214 2639-6838 7 CN7215F 2639-6853 8 CN7216F 2639-6861 9 10 11 CN7217F 2639-6879 12 CN7642F 2641-4938 13 AM9218BCC 2641-4946 14 C48143 2641-4953 15 C48144 2641-4961 16 CN7792F 2641-4979
Here is a link to some of the information have gathered
Burroughs TD833 - Google Drive
drive.google.com
Sure. I will check the power supply voltagesAs it happens I acquired one of these terminals yesterday, a TD833 with a REV D CPU board. My initial attempts to dump the ROMs were unsuccessful however I understand where I went wrong and am in the process of making an adaptor so I can read the AM9218s as a 27128, effectively mapping the three CS pins to A11, A12, and A13.
The way the ROMs are generally wired can be seen in the image below.
View attachment 1258464
The address lines and CS lines are common to all ROMs
The 16 ROMs are in two groups of 8 each with a data bus each, a bus is selected via the CPU using some N8T97N (tri-state).
I don't know where the CS lines are derived, however, they can't be directly mapped from the address bus as there is insufficient address space.
Incidentally, it would happen that my power supply is also not working, any load on the 5V rail, and the power supply shutdowns. Cliff if you could possibly provide me with a list of voltages and their location I would appreciate that greatly. I have seen 5v 20v -21V however I don't know if there are more. One of the 5v regulators looks to be shorted to ground too, or perhaps it's just off.
Here is a table of the ROMs this system has.
Slot Chip MAKS label 1 2 3 AM9218BCC 2641-4904 4 CN7640F 2641-4912 5 AM9218BCC 2641-9465 6 CN7214 2639-6838 7 CN7215F 2639-6853 8 CN7216F 2639-6861 9 10 11 CN7217F 2639-6879 12 CN7642F 2641-4938 13 AM9218BCC 2641-4946 14 C48143 2641-4953 15 C48144 2641-4961 16 CN7792F 2641-4979
Here is a link to some of the information have gathered
Burroughs TD833 - Google Drive
drive.google.com
Hello there,Cliff, would you make your rom dumps available?
I made a table of rom part numbers from the three cpu boards over the weekend
it is at http://bitsavers.org/pdf/burroughs/Terminal/TD83x/TD831_CPU_bds/romlist.txt
Someone offered to send me a box of Burroughs service microfiche, hopefully more
terminal information will be in there.
Also, I am REALLY curious where that image on the screen came from.
Do you have a running Burroughs system?
Is the data the same in them between the different boards?Just another topic. The CPU and Video PCB contain PROMS 82S123. I have save the data with an adapter.