Televideo TS800A Repair Part2
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- Опубліковано 7 вер 2024
- It appears that my initial assumption as to the identity of this vintage machine was incorrect.
I will need to alter the title of the previous video.
I had assumed it was a Televideo 950 but it seems to actually be a Televideo 800A/950.
This is another very interesting machine that I wasn’t even aware it existed. I quickly went online to find manuals and schematics as the curiosity arises immediately. It seems that both processors share the memory. As the 950 part also doesn’t work might be part of the problem. It would be very pleasant to see the process of faults finding. Thanks for bringing this device to our attention.
Yes it is certainly interesting. The processors do not share as much as it appears. As far as I can tell the 950 and TS800A schematics have simply been put into a single set of schematics but the signal designations have not been altered to reflect this. For example if you look through the schematics there seems to be a common /RESET line but it is not a single reset. It is split from the 950 to the Z80 but they are all all called /RESET. You have to look at the sheet numbers alongside each signal to see if they are the same. This is also true of many other signals. They do however share a common set of control lines to allow the two parts to work together. They mostly communicated through a single SIO channel. I hope to show some of this in the following videos.
I am looking forward to your archeology on this interesting machine. What might be the use case for a terminal married with a CP/M machine?
They were intended for use in a multiuser development or work environment. The 422 interface allowed multiple machines to be connected together and share information across selected users or to connect to process controllers.. Remember this was before the internet and modern networking existed.
Would you be able to share ROM dumps from this machine, for emulation purposes ?