proto trak lcd upgrade

[hdokes]

Ok... making limited progress.....

Discovered that not only was the display bad in this lathe but the power supply for the main pc was also bad. Assuming that the 12 volt supply to the monitor was probably shorted with the burned out transistor in the monitor.

Set up a newer atx style power supply with the appropriate voltages. Installed the graphics card into the pci slot and hooked up an LCD monitor. Damn if the system didn't come alive when I turned on the power supply. Got video on the screen and in color..... issue is.... only got the post test stuff on the screen.

Initially the floppy drive would not boot but I did not have the co-processor board and it's daughter board installed. So I installed them and the floppy was able to boot at that point. MS-DOS.

That's where the fun ended. It is my guess that video at that point is redirected to, or then generated by, the co-processor board and out to the original crt. As I stated it has a 68000 processor on the co-processor board (the same used by the old Macs) and some sizable firmware ROMs.

As I have never actually seen the entire boot cycle of the Proto Trak system I'm not certain what I should be seeing after the "Booting MS-DOS.........". The floppy runs for a few seconds after that comes up at which point I'm sure it turns control over to the co-processor board. I am a bit familiar with this type of operation as the old Apple][s used this same method with the Z80 co-processor that you could plug into the backplane to run CP/M. Difference was it still used the same display circuitry to route the visual data through.

So..... I'm kind of at a stand still here, again, possibly or likely looking at the need for a video converter from MDA to VGA. Going to see if I can pick the boot floppy apart to see if it is actually doing the redirection of the video through the co-processor board.

If anyone could chime in that would be JUST Duckie!

[BillTodd]

hi hdokes,

I have played with 'prototrak' equiped lathe ( not sure of model) but only to fix minor connection problems in the control box (if i recall correctly, the pc part slides out one end of the box?)

From your description, it does sound like swi are geneating the video on the 68k board . If so, you may be stuck having to find a MDA compatible lcd (from where , i do not know) or some kind of adapter / converter. From (failing!) memory the frequencies are in the TV region, so there is some hope that one of the cheapo lcds will only need some sync signals adjusting to work.

Bill

[pwndeyada]

Hoping someone will see this -- I've been working for weeks to get the AGE 3 to output display to an LCD (existing CRT damaged and output distorted). I've tried multiple PCI VGA cards, multiple LCD monitors, leaving the existing MDA card in & removing it, all to no avail. The system boots normally (at least the buttons beep and respond per usual) but no display gets outputted to the LCD screen (powered through separate wall outlet). Might try finding an old ISA VGA card instead of using the PCI slots, but it seems PCI has worked for others... If anyone has any suggestions, that'd be greatly appreciated!

[Pikaldi]

I recently bought a Liliput monitor, I left a very good impression. That's why I can recommend them.https://lilliput.net/

[richardgarth]

I recently bought a Liliput monitor, I left a very good impression. That's why I can recommend them.https://lilliput.net/

It would be very helpful to know which monitor you got from Lilliput? Did you have to modify the connections or was it straight forward?

Thanks

[morbidelliuser]

Anybody tried this?

https://www.converters.tv/vga_to_vga...nitor/563.html

Looks like it should be a fairly easy install.