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RE: [N8VEM-S100:105] Re: S-100 Motherboard

Hi Rich!  Thanks!  That's great news!  I am looking forward to starting on
the S-100 6502 CPU board!

Have a nice day!

Andrew Lynch

> -----Original Message-----
> From: n8vem...@googlegroups.com [mailto:n8vem...@googlegroups.com] On
> Behalf Of Rich Leary
> Sent: Saturday, March 05, 2011 11:39 AM
> To: N8VEM-S100
> Subject: [N8VEM-S100:105] Re: S-100 Motherboard
> It has been a busy few days with a 10-12 inch storm on Thursday night
> - Friday morning to create a diversion. Here is status:
> a. CP/M and DOS/65 are working fine.
> b. I found the original Xebec utilities I had modified to set up my
> hard disk (CMI 5619). I reformatted the CP/M partition to eliminate
> the error in one of the directory sectors. This left the DOS/65
> partition intact but did delete all the CP/M files from E:. I had a
> backup on 1.2 MB floppies and was able to restore all the files that
> were on the backup diskette set. What is fascinating is that the
> diskette set had none of the .ASM or .Z80 files nor were they on the
> E: drive before I reformatted that partition. I did have copies of the
> key source files (i. e., my BIOS, my BOOT, my monitor ROM, hard disk
> setup utilities, and three of the four diskette format routines) on my
> PC backup. Why there were not more on either disk or diskette set is a
> mystery and since the last time the CP/M system was used was 15 years
> ago my memory is foggy about what happened. I recall having
> accidentally deleted some files but why both .ASM and .Z80 files would
> have disappeared in one step is a mystery.
> c. I looked hard at what else I had and what I needed and concluded
> that the key immediate need was for a high speed MODEM7 variant to
> facilitate PC to S-100 transfers under CP/M. I had a binary version of
> MODEM798 set for the Interfacer IV but it was only configured for 4800
> bps and I wanted to use 19,200 just as my DOS/65 software can do when
> the 6502 CPU is installed. I eventually settled on MDM727.ASM as the
> SIG/M archives had an overlay for the Interfacer IV. Silly me - I
> thought it would be a no brainer to set the parameters in the overlay,
> merge the files, and charge ahead. It turned out that the overlay had
> several coding errors that manifested themselves as soon as I ran
> ASM.COM on the source file. While these errors did not take too long
> to fix it is fascinating that the code had been in existence since
> 1984 with some very obvious errors. The problem was that the errors
> were only obvious when changing the default conditional assembly
> variables. In the end it was a simple few fixes and MDM727 is now
> workign at 19,200 with an approximate character (byte) transfer rate
> of 1350 characters per second. Having that working well makes it much
> easier to add software, work on it in multiple environments, and in
> general take a more controlled and timely approach to moving files
> around.
> d. I am now looking at adding either NetBurner Serial to Ethernet
> devices or perhaps Zigbee Serial to Wireless Ethernet devices to the
> S-100 system both for the console port that currently uses a Wyse
> Wy-50 terminal as well as for the "modem" port driven by MDM727 and
> the comparable DOS/65 software. That would give me a lot more latitude
> in physical placement of the system as well as ability to do things
> with it from multiple places in the house by using the home network
> (both wired and wireless) for connectivity. Anybody have experience
> with these devices?
> e. I had not finished the revised 6502 CPU schematic as I was missing
> a key sheet. I found that yesterday so I should be able to finish it
> in a few days. I need to re-copy some of the sheets as I was using a
> Sharpie to do the markups and the sheets were just getting too messy.
> Rich