Building your own home computer - Hardware

Background:

Project steps:

1. Design a modular TMS9995 based micro computer with 8 KB (EP)ROM and 56 KB RAM.


2. Extend the design with a display interface based upon the V9938/9958 from Yamaha. This makes debugging so much more easier.
3. Extend the design with a storage and keyboard interface.
4. Upgrade it to a TMS99105A/110A based computer.
5. Upgrade to dual CPU design using two TMS99105A/110A CPU's.

Project updates:

• 02/25/2005 - I've written a TMS9900/9995 cross disassembler for WIN32. You can find it here.
• 02/20/2005 - The TMS9995 based micro computer page is updated almost daily.
• 11/09/2004 - I hope to get my TMS99105A/110A's within days now.
• 05/22/2003 - Today I received the eight V9958 VDP's I want to use for the project.
• 05/13/2003 - I found a US supplier for the TMS99105A. They sell the chips for a price of $160. To bad the price is to high, to keep the project affordable.
• 05/10/2003 - I noticed people trying to e-mail my using the e-mail listed at the end of this page. They probably got a SMTP 501 error back. I've changed my SPAM filters to be less restrictive. Please feel free to try again.
• 05/10/2003 - I don't know what it is with US suppliers. None of them react on my e-mails. They obviously think in $$$ and a lot of them.
• 05/09/2003 - Last week I found a supplier in the NL for the 74LS610 & 612 MMU's. This supplier is almost at the corner of the street I work, couldn't be better. The only disadvantage is that they don't sell to private person, but that's no problem according to my boss... ;-)
• 05/09/2003 - I found a UK supplier for the TMS99105A. They sell the chips for a price of £125 + VAT. To bad the price is to high, to keep the project affordable. I'll try my backup supplier now. ;-)
• 05/08/2003 - I might have found a Dutch supplier for the Yamaha V9958 video display processor.
• 05/08/2003 - I also found two US suppliers who have also over 2000 TMS99105A/110A on stock. The first has a line order per part of at least EUR 500, the second, didn't answer my e-mail yet...
• 05/08/2003 - Yesterday I found a supplier in Swiss that has over 2000 TMS99110A chips on stock. The only drawback was the price per part, EUR 150,-.
• 05/08/2003 - The inventory DB is more or less finished. Every part I get my hands on, will be put into this DB.
• 04/29/2003 - I'm busy creating an inventory of all the different types of IC's I have. I estimate that I have more then 1000 IC's.
• 04/25/2003 - I discarded PC-Trace as PCB layout program, I'm now using Eagle 4.09r2 which is a schematics, PCB and auto-router creator program. Since no TMS series libraries exist, I'm busy creating them myself. This needs to be done or else it's rather pointless to create schematics.
• 04/24/2003 - Rene van Geijn, a colleague of mine, came up with a name for an OS that needs to be written for the micrcocontroller, Retro OS or RetrOS (C)(R)(TM) for short. No, it's not patented (yet) or is it...;-).
• 04/18/2003 - Updated this website.
• 04/16/2003 - Started with reading all the relevant technical papers about the components I want to use.
• 04/16/2003 - Removing the dust from the ideas, scratch designs I made last year.

Project related links:

• To view the list of all the IC's I currently have, click here.
• To view the CMOS/TTL IC delay characteristics, click here.

Comments, ideas or suggestions: