Recent content by oldcomputerexpert

Could you post a photo of the CPU board schematic?

Unfortunately, that's the same one that's on Bitsavers.org. It is part 1 of 2, and doesn't include the troubleshooting and schematics.

I know Bitsavers.org has part one of the service manual for the 810, but part 2 of the service manual that has the troubleshooting and schematics is missing. There is a complete service manual for an 820, however it's completely different from the 810. I'm restoring my 810 I have had in...

Denied access too... I guess DasmxComment.exe is no longer available, which is too bad, just what I was looking for. If anyone has already downloaded it please re-post.

I don't think you will find any Windows drivers for the 4663 plotter. It's just too old. You will need to send the plotting commands from a terminal window, or write a program to send the move & draws.

The way I have been able to communicate with my 4663 is through the MODEM connector at 1200 baud (not the TERMINAL connector). The MODEM connector is probably wired DCE, so you may need a null modem (crossover) to connect to a PC. You can check that you have TX from the PC to the RX by...

I would also be interested in the ROM pack. I had started to put together a design a couple years ago, but it got put on the back burner when I went onto other projects like my 4052 restoration. My desighn was to emulate the 4051E01 with 8 ROM images, and possible a RAM block that you can...

I am looking for the service manual for any of the early Interdata systems. I have an Interdata Model 1 that I would like to restore. It uses 10-inch boards that were common in other early Interdata systems, like the Model 3. I have a user's manual for the Model 1 which has the instruction...

I'm not sure what happened to the photo in the previous post, but here it is again. The circuit is basically U481a of the tape board schematic (early rev. board) that connects to pin 34 & 26. and tie the Loaded signal low (pin 19). If you build one be careful of the connector pinout, Tek...

Progress!! I had found that several of my firmware ROM's were bad so I set out to replace them with the latest image available for the 4052 (version 5.1). The only known EPROM with the same pinout as the MK36000 ROM is the MC68764, however with a 400ns access time it is much slower than the...

I finally got my subscription to the DataIOEPROM group approved also. I have the original UNIPAK (not the 2 or 2B) and the device list indicated the WSI 57C49... needs V11 on the original UNIPAK. I was disappointed that the V11 firmware files were not included in the files section. The V11...

I have a Tek 4052, or at least most of one, I'm missing the tape drive and some of the case parts. I received it mostly as parts. I'm trying to bring it back to life. I currently have it set up in a diagnostic configuration, spread out on a table so I can get to the board test points. I...

4051 rtc 4051 rtc I have the 4051 version of the TransEra RTC, model 641-RTC. I have a dump of the EPROM if anyone is interested. It doesn't have any PAL's and it's built around an AM8253 with a few 7400 series chips and a couple other analog chips for the crystal oscillator circuit. The...

I have had this system in storage for about 33 years now, so I thought I would pull it out and get it working. After replacing a capacitor on the memory board and cleaning contacts on the tape drive I was able to get it powered up. I had to figure out the pin connections and baud rate on the...

I have a couple Interdata Model One systems I have been trying to bring alive. I have a couple stuck bits to resolve, but work is slow having to debug without a schematic. I have documentation on the instruction set and a user guide, but no service manual. Hopefully someone in the group...