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+--- Thread: Z80 S100 DGZ680 system (/thread-760.html)
Z80 S100 DGZ680 system - vk7hch - 05-01-2024
My mate brought down his DGZ680 last night. It is built into a 19" rack mount.
It has I think 6 cards in it, I am at work, so I will edit this post when I get home to list the cards and looots of pictures.
I know it has a Microworld Basic card in it with 6 roms on it. There is an "Economy 16K memory card", a DGZ640 card and several others.
This looks like a fun project.
I am awaiting a FABGL card to arrive to make a serial terminal.
First step will be a full clean and diagnostic on the power supply.
More to come.
RE: Z80 S100 DGZ680 system - someone - 05-01-2024
Great stuff!
Prior to initial power up it may be a good idea to reform the large electrolytic capacitors because they can be expensive to replace.
RE: Z80 S100 DGZ680 system - vk7hch - 05-01-2024
Here we go:
RE: Z80 S100 DGZ680 system - CheshireNoir - 05-01-2024
What a beast!
16K on one board and 28K on the other?
Hope to see this running one day :-)
John
RE: Z80 S100 DGZ680 system - ChickenMan - 05-01-2024
Fantastic, yes would be good to see it running. Thanks for the pictures, any chance of a dump of ALL the roms ?
RE: Z80 S100 DGZ680 system - someone - 05-01-2024
Yep, definitely reform the capacitors if you can.
What you've got is essentially most of a pre-microbee microbee.
A serial terminal is not necessary.
The video output is via the MW640 card to a composite video monitor.
However you do need a parallel interface ASCII keyboard for input.
To save to and load from tape get an USCI or SECI.
To get HIRES graphics and joystick support get a TCT-PCG card.
Seemingly unintuitively, after removing all cards & testing out the power supply and ensuring it outputs clean unregulated +8VDC, -16VDC and +16VDC, you should hook up just the MW640 VDU card and see if you get video output.
RE: Z80 S100 DGZ680 system - someone - 11-01-2024
Note that there are 3 voltage regulators on the S100 motherboard.
These are here to supply additional regulated voltages for peripherals such as keyboards.
Usually the regulated voltages are -12V, +12V and +5V and limited to a maximum of 1A on each.
However you'll need to ensure that adequate heatsinking is provided for the regulators for the intended load.
RE: Z80 S100 DGZ680 system - someone - 12-01-2024
Resist the temptation to run your system at 4MHz until you upgrade the necessary items to do so.
The RAM you have on your MW640 is only rated to run at 2MHz.
The BASIC ROMs and DGOS ROM are only rated at 2MHz
The Z80 PIO and CTC are only rated at 2.5MHz.
However the RAM on the DGZ80, AT16K RAM Card and other RAM card should work at 4MHz
RE: Z80 S100 DGZ680 system - someone - 24-01-2024
One of the D25 connectors on the rear looks configured for a parallel ASCII keyboard and has one of its pins assigned for the regulated +5V from the motherboard.
If you can't source a parallel keyboard you can kludge one up using a PS/2 or USB IBM PC keyboard and an inexpensive small microcontroller such as the PSoC 5LP or AVR.