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Vintage Computers Any vintage computer systems, calculators, video games etc., but with an emphasis on 1980s and earlier equipment.

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Old 17th May 2019, 6:37 pm   #61
JohnBHanson
Hexode
 
Join Date: Aug 2009
Location: Worthing, Sussex, UK.
Posts: 341
Default Re: Gemini 80-Bus System

Once you have 32k CP/M running from disk the rest is easy

create a directory on you system ~/beaver/network - this will hold "network files"

run xbeaver with the 64k cpm file. within the emulator type

A>t-net n
A>pip n:=a:*.*

This will copy all files on a: to the network drive (eg the linux directory ~/beaver/network)

Copy t-net.com from there to rp/m using your existing technique via rpm
boot your 32k copy of cp/m disk on the real hardware (this will not destroy the program area)
use the save command to save the file t-net.com to disk

check the access permissions on /dev/ttyS0 allow access - change if necessary
then on linux run
xbeaver fileserver

on the real gemini system run the command
a>t-net n

Then any files in directory ~/beaver/network will appear in drive n: of your gemini machine
these can of course be copied.

To create a copy of the 64k system in real sectors do the following

a)extract icopy.com from xbeaver.dsk do the following
run
xbeaver
A0:0>copy a:icopy.com n:



B)
Translate the .DMP file to a .dsk file

in the gemini.cfg file change the floppy command to be use the line (or similar)

board 0xe0 gm829_floppy -geometry D35.2.10.0.512 ~/beaver/gm512/GM512_64.DMP C35.2.10.0.512 ~/beaver/network/cpm_64.dsk

now run xbeaver gemini.cfg

copy the program icopy.com into a: using
A>t-net n
A>pip a:=n:icopy.com
A>icopy
Source Drive>A
Destination Drive>B

This should copy the disk to the disk file
~/beaver/network/cpm_64.dsk
exit the simulator


On the real hardware the file n:cpm_64.dsk contains an image of the disk

use the following to create this onto drive b:
n:disked
Disked>Db (Echos as Disk B)
Disked>Fs (Echos as File set) n:cpm_64.dsk)
Disked>t0 (Echos as track 0)
Disked>s1 (Echos as sector 1)
Disked>Fr (Echos as File Read)
Disked>Q (To quit disked)

(Disked ? gives help)

This will copy the file cpm_64.dsk from the linux machine to disk b:

And you will have (hopefully) a CPM 64 k disk in drive B:

DIsked will be a useful tool for you. If you do Buffer read/write disked holds its buffer at 2000h and can be pre-loaded as required before running disked (including via rpm).
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Old 17th May 2019, 8:57 pm   #62
JohnBHanson
Hexode
 
Join Date: Aug 2009
Location: Worthing, Sussex, UK.
Posts: 341
Default Re: Gemini 80-Bus System

Just to let you know that I enjoy your glasstty.com 6502 viewdata
service.

A while ago there was a viewdata/prestel card for sale on ebay that was 80bus
so I had to give into temptation and implement it in xbeaver.

The config line to get the screen is

board 0x47 wt625 0xfc800 Viewdata options kahsv

also make sure you have the shell server in your config:-
board 0x48 shellserv /bin/bash

And to run it within VPM/M the following commands
are useful. To start a virtual machine on the terminal type the
following

device ins a:vv
device vdu vv0

and then run program viewdata to get a linux shell, from there telnet glasstty.com 6502
or as you want.

Another test program
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Old 17th May 2019, 10:39 pm   #63
john_newcombe
Triode
 
Join Date: Apr 2019
Location: Skipton, North Yorkshire, UK.
Posts: 29
Default Re: Gemini 80-Bus System

I am glad you like Telstar, it has been very popular with BBC and Sinclair owners. Thanks for all your help and information I am working through it all. Will let you know how I get on with it all.
J
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Old Today, 7:48 am   #64
john_newcombe
Triode
 
Join Date: Apr 2019
Location: Skipton, North Yorkshire, UK.
Posts: 29
Default Re: Gemini 80-Bus System

Just looking at patching CP/M for serial and just wanted to check with you on the 'status' patch.

I am performing the patch within the script performing the conversion from .DMP to .IMG so that I can produce both patched and non patched automatically and the byte I see at F6EF (64K) doesn't match with the one you mentioned so my maths is probably wrong.

Given that I have a interleaved .IMG in memory as a byte array I can see that the first patch is at byte 6125 i.e. 12th (512 byte) sector, offset 31h. This ties up with the value at the end of the list of C3s. So I am happy with this patch.

The second patch 'status' I am not getting right. Based on bytes 3 & 4 in sector 0, I am using CP/M with the load address of 5D00, the 64K image you sent shows a load address of dd00. My maths suggests that a patch at F6EF on a 64K system relates to byte 1Bef within the byte array...

Code:
Patch Address - Load Address + Length of Sector 0
F6EF - DD00 + 0200 = 1BEF
...but this byte is 02 on each disk image not 20h as you suggested, can you see what I am doing wrong?

J
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Old Today, 8:36 am   #65
JohnBHanson
Hexode
 
Join Date: Aug 2009
Location: Worthing, Sussex, UK.
Posts: 341
Default Re: Gemini 80-Bus System

You need to take the address of the patch 6ef, add the base of the bios f300 to get f9ef and then
work out
f9ef - dd00 + 0200 = 1eef

This should be 20h and you need to change it to 01h

Try that.
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Old Today, 9:36 am   #66
john_newcombe
Triode
 
Join Date: Apr 2019
Location: Skipton, North Yorkshire, UK.
Posts: 29
Default Re: Gemini 80-Bus System

Thats it, many thanks.
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