TMS 99105 Project PCB Available

[Stuart]

I've taken my TMS 99105 (TMS 99110) breadboard project and made a PCB for it. Simple system - processor runs at 4 MHz, two pages of 32K RAM, two pages of 32K EPROM, and an RS-232 serial port to communicate with a terminal program on a PC. Runs a system monitor, Cortex BASIC and Forth. No means of saving programs, but you can maintain/edit them on the PC and download them over the serial link. On the PCB, there are take-off points for all the main signals including the demultiplexed address and data bus, if you want to expand it further.

 

I've got a couple of bare PCBs spare - anyone interested? £16 each plus postage to you from the UK. There are full details plus approx. cost of the components here: http://www.stuartconner.me.uk/tms99110_breadboard/tms99110_breadboard.htm

 

PM me if interested.

 

[jedimatt42]

PM sent

 

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[jedimatt42]

It arrived It is beautiful. I just love looking at bare pcboards. The rest of the parts should be here this week. It makes me nostalgic for my old vt220.

 

Of course the pc terminal will be more friendly, and allow for pasting code in I may have to begin assembly tonight.

 

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[+Ksarul]

Yes, mine arrived today too. They are beautiful bits of work. Many thanks for making these, Stuart!

[speccery]

Got mine about a week ago, nice board indeed - now all I need is time to build it But that has to wait for FinalGROM99 login analysing & debugging and a few other things... I hope I still have narrow 32k SRAM chips lying around, but I think I do.

[jedimatt42]

Mine's almost built. I'm being teased by e-bay... my latch chips have had the label printed, but USPS hasn't received them yet... and they're scheduled for delivery tomorrow gotta love that...

 

Given the memory timing writeup, I would think some 15ns gal16v8 chips I have on hand could be used for the latches if I rewire pin 1 and 11. Those have to be clk and oe respectively on the gal, but are the other way around on the '573 latch.

 

Time to sleep on it before things get too weird.

 

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[jedimatt42]

Ok, well the gal's didn't work even with the funny wiring... maybe I made a mistake, or didn't get my facts right on the LE level or something...

 

The real chips showed up, and I cleaned up my shenanigans, popped them in, wha-lah: It almost worked.. the output was garbled, but then I remembered, Stuart, you seem to like 7 bit serial. Changing the terminal settings to 7n1, and pressing the reset button yields:

 

TIBUG REV.B (comms 19200-7-E-2)
Modified by Stuart Conner
Press ? for list of commands

Which clearly shows, I should change it to 7-E-2

 

I'm re-learning assembly while trying to write a DSR for TI storage. This will surely help me build that skill. I'm realizing, I have a ton of knowledge (minus the hundreds of tons I don't have), and very little skill

 

-- Now to try the more basic rom --

 

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[Opry99er]

Sweet.... I look forward to updates.

[Opry99er]

Matt, what was the total BOM cost, if you don't mind me asking?

[jedimatt42]

Matt, what was the total BOM cost, if you don't mind me asking?

I couldn't answer that... I bought e-bay parts in quantities more than I needed, and had half the parts on hand already. You could cut-n-paste the cost column from here:

http://www.stuartconner.me.uk/tms99110_breadboard/tms99110_breadboard.htm

Drop it into something that adds columns of numbers up, and then convert that to US Dollars ( * 1.25 right now according to Google )

 

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[Opry99er]

I saw that list... Wasn't sure of the exchange rate though, and what parts I would not need since we are on a PCB now.

 

I'll calculate now with the 1.25 and get.a best guess. Thanks!

[jedimatt42]

I saw that list... Wasn't sure of the exchange rate though, and what parts I would not need since we are on a PCB now.

 

I'll calculate now with the 1.25 and get a best guess. Thanks!

The only thing in the list not used on the pcboard is the first item, the bread-boards. Strictly speaking, you don't have to populate the 'spare' eprom sockets, that is 2 of the 28 pin 0.6" wide sockets.

 

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[Opry99er]

Looks like (including PCB) it will be around a bill.

 

[Stuart]

Just a note that all my spare PCBs have now gone. I'm happy to order some more if a couple of people are interested, but they're likely to be more expensive, depending on whether or not those nice people at Sitopway include any spares in the order.

 

Stuart.

[Stuart]

I've got some more PCBs for building your own TMS 99105 or 99110 system if anyone is interested (also more PCBs for the TMS 9900 system - see http://atariage.com/forums/topic/267619-tms-9900-project-pcb-available).

 

Cost is £26 + postage to you from the UK. This will get you:

 

-- a PCB

-- D-type 9-pin socket

-- DC power socket

-- 2 off W24257AK-20 RAMs

-- 2 off 74ALS645AN transceivers

 

For the other components you need, see the link in the first post on this thread.

 

Send me a PM if interested.