Genie IIIs boots CP/M but can't boot NEWDOS or GDOS

[fritzeflink]

Hi..
I have a TRS-80 compatible Genie III S made and sold in Germany by Trommeschlaeger. This G3s has 256k, a Boot rom and no basic rom so it maybe similar to the Modell IV.
The G3S was sold with GDOS 2.1 - a NEWDOS translated and modded for german users.

So the short introduction.
I have CP/M 2.2 and CP/M + from 2 different programmers and the G3s boots without any problems.
BUT - if I want boot NEWDOS or GDOS the System got angry..
After some access to the floppy disk the screen is completely filled with 9@9@... and then after a short wait some places on the screen are filled with other characters .. then it stopped.

I did:
I checked the mainboard and found no damages, all chips are clean, no rusty contacts
I checked the rams, replaced bank0 with them from bank1 and visavi
I replaced the video controller 6845
The voltage of the psu are ok.

Nothing helped and there must be some initialization by NEWDOS which makes the Genie ill.. :-(
NEWDOS may find a bad TTL and CP/M doesn't care.

My documents are mostly in german language so this will not really help for most of you but here are some links. I don't believe that the G3s was sold outside of germany.

Picture:
http://oldcomputers.dyndns.org/public/pub/rechner/eaca/My_Genie_IIIs/bilder/G3s_board_web.jpg

Running Harddisk Video with OMTI PC-HD-Adapter 55xx:
http://oldcomputers.dyndns.org/public/pub/rechner/eaca/My_Genie_IIIs/bilder/G3s_ZCPR.mpg

Some manuals.
http://oldcomputers.dyndns.org/publ...uals/Technische_Beschreibung_zum_Genie_3s.pdf

I like to get my my NEWDOS back....

 

[Tibs]

I know nothing about this machine, but I wonder if its a bad chip in a higher memory range than CPM uses.

 

[pski]

Look at all of those socketed chips! I'd recommend reseating all the chips but you might try to hit me!

 

[Audronic]

@Fritzeflink

Ok Don't hit pski .

It looks like on the Model 1 if the roms are removed you get that pattern on the screen.
1) Please unplug the CPM ROM check the contacts and plug i back in about 3 times to help clean the socket.
2) Do you have an the copy of the Newdos, is try that.

Good luck Ray

 

[fritzeflink]

As the Genie 3s is compatible to the Tandy M1,2,3, is is more than that.


As there are some need able initializations which are different for CP/M and for NEWDOS I believe that
for NEWDOS they got bad.

I will replace some LS244 / LS245 as bus driver and of course the LS138 (Binaer decoder) and LS273 (8bit register flipflop)
as I have no hardware for measuring and only a basic knowledge of all.


I / O port assignment: Genie III S

Within the system are 41 fully decoded Z-80 I / O ports. A precise determination of the addresses and
A description of the functions can be found in the following pages.

L.Nr. Adre .: Hex, Dec Short description:

01   D0-D3, 208-211      Z-80-B SIO / O
02   D4-D7, 212-215      Z-80-B PIO
03   D8-DF, 216-223      To be reached via BUS
04   E0-E3, 224-227      Drive Select
05   E4-E7, 228-231      not used, but locked
06   E8-EB, 232-235      Printer port
07   EC-EF, 236-239      floppy controller register
08   F1,      241            Baud rate setting
09   F2,      242            BTx Switchover
10   F6-F7, 246-247      Video controllers, registers and
11   F9,      249            System byte 0  initial parameter
12   FA,      250            System byte 1  initial parameter
13   FD,      253           Printer port
14   FE-FF,  254-255     Screen format 1: 1, 1: 2

The init-loader checks what system is to be booted and then changes  CRTC, ROM, RAM and Speed configurations.
using system-byte 0 and 1 


The Genie III S Init Loader

The init loader is part of the ROM area.To initialize the system after power up or RESET the sequence is as follows:

1. Test whether Power-On or RESET. 
    If Power-On => Character set load.
    If the F8 key is pressed at the same time, the
    Character set is also reloaded, the memory area of
    4000 - 4FFF, 16384 - 20479 is destroyed.

2. Check if the Fl key is pressed. If yes => Monitor

3. Read TRACK 0, SECTOR 0 as in the B command, page 29 be
   wrote. The value that the loader is attached to the relative
   Position E0, 224 of the sector decides further boat run. 
   The following applies:

01 => Default for Genie III S G-DOS floppy disks. Of the
         Loader sets system byte 0 to 00 and system byte 1
         To C4, 196. Thereafter, TRACK 0, SECTOR 0 to 4200,
         16896 booted and jumped after 4200, 16896.

02 => Default for Genie III S CP / M floppy disks. Of the
         Loader sets system byte 0 to 01 and system byte 1
         To C4, 196. Thereafter, TRACK 0, SECTOR 0 to FC00,
         64512 and jumped to FC00, 64512.

03 => Default for Genie III S service disks. Of the
         Loader sets system byte 0 to 00 and system byte 1
         To 04. Thereafter, TRACK 0, SECTOR 0 is set to 0000
         And jumped to 0000.


The memory location 2FFF, 12287 is set to the value B2, 178 testing. 
If the loader finds this value, system byte 0 is set to 000 and system byte 1 set to E4, 228, TRACK 0, SECTOR 0
After 4200, 16896 booted and after 4200, 16896 leaped because with it is possible to use standard G-DOS or NEWDOS 80 diskettes
For SpeedMaster 5.3, GENIE I / II or TRS 80. Should they are floppy disks, which are recorded in SINGLE DENSITY
the "fire button" must be pressed, The system can record such disks only with a clock rate of
1.78 MHz.