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Re: MYIDE



No - I am about 25% complete on assembly. My S-100 time has been focused on getting my 6502 V1 CPU working. You would think since the design was originally mine based on my 30+ year old wire wrap 6502 S-100 CPU it would be an easy debug when it did not work right away. There were no assembly errors or mistakes and while there are a few comments I am going to write up for a builders notes file, the issues were all timing related. First mistake was using ALS ICs where possible - just too fast! Second mistake was in not noticing that since the PH2 clock true period that defines the read and write strobe duration was 250 nsec there would be a problem with the terminal USART (2651) on the Interfacer 4 that had a minimum CE width of 300 nsec. Adding one wait state solved the problem - everything working as intended. My old wire wrap board is also running at 2 MHz but did not have this problem since it was using a G65C102 that has a "PH4" clock output that allows a 375 nsec strobe duration and no wait state needed. Since I have bought some time with the wait state I am going to try bumping the clock up in 0.5 MHz increments to see if I can get some more speed out of the beast.

I converted and did some minor cleanup on the MYIDE (org 100h) version, I am a few days away from finishing my board so it will be a few days until I can provide any actual use experience.

File attached.

Rich

On Saturday, June 7, 2014 10:09:12 AM UTC-6, Thomas Owen wrote:
Rich,
Did you get your IDE board working?  Which version of the software did you convert, the MYIDEROM or MYIDE?

Thanks for your work,- it will save me a lot of time and Hopefully I can get my board up and running.

Thomas

Attachment: MYIDE291.Z80
Description: Binary data