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Hi Jeff,
Yes, you can either... jumper the board so Shadow ROM is not present (ie, remove the ROM jumper for address block 0) OR, much easier to simply RUN, then STOP, but do not hit reset. The RUN will kill the Shadow ROM (making block 0 all RAM), STOP will put the CPU back to a WAIT state and re-enable the front panel. Now, to enter, just Examine address 0000, then Deposit and Deposit Next your program. When you are ready to run it, just Examine 0000 and hit RUN. Do not use RESET anywhere that will re-enable the Shadow ROM. By doing an Examine 0000, you are really causing a CPU JMP instruction to 0000, which puts the PC at 0000, now you may single step or run through your program. Regards, Josh Date: Mon, 23 Feb 2015 08:04:33 -0800 From: jeffrey.h...@gmail.com To: n8vem...@googlegroups.com Subject: Re: [N8VEM-S100:6421] Re: IMSAI 8080A CPU board help. On Monday, February 23, 2015 at 7:03:35 AM UTC-7, Crustyomo wrote:
Ahh hah! That explains why my original burn of a 25256 didn't complete the boot. I didn't realize the jumper settings changed between the 1.2 and 2.3 releases of the loader. I had been experimenting with the position of that jumper while attempting to input a small program with the front panel - after entering a short front panel input test, from the Imsai manual, I'd hit run and the ROM would take off. Is there a way I can experiment with entering a test program from the front panel and running it without the boot loader ROM taking over? -- You received this message because you are subscribed to the Google Groups "N8VEM-S100" group. To unsubscribe from this group and stop receiving emails from it, send an email to n8vem-s100+...@googlegroups.com. For more options, visit https://groups.google.com/d/optout. |