We’ve enjoyed seeing the development progress of Veronica, [Quinn Dunki’s] 8-bit computer project. It started out on a breadboard, then moved to edge-connected PCBs, and now [Quinn] has given Veronica a body of her own.
The donor is a Philco Model 42-327T and was produced in 1942. It was chosen because it is non-functional and missing several pieces. We wonder about the collector’s value of the piece but since [Quinn] snagged it from eBay there can’t be in huge demand right now. The teardown images are priceless. There seems to be no reasoning behind component placement for the beast. It looks more like a junk drawer packed full of relic components than something that actually worked once upon a time.
But we digress. After gutting the retro wooden case [Quinn] set out to fabricate her own face plate. Since she’s comfortable working with copper clad, she whipped up a negative design and etched the dashboard seen above. It mounts in the original dial opening, and hosts all of the controls she needs to work with the 8-bit computer. Just below is where the present buttons used to be located. You can just see the hexout display for reading data from the registers mounted in that void.
Very nice, but just some aesthetic nit picking, she had three perfectly usefull knobs on the front, should have used them for three of the switches and she should but a piece or plastic over the hex display semi-opaque for a cleaner look, still better than I could ever do.
the thing about vaccum tube equipment that people will NEVER EVER EVER EVER let you tell them (cuz they are stubborn ect)
… is you do NOT “just plug it in” and “see if it works” !!!!!!!
usually the electrolytycs will have shorted! sometimes fail opened.
these are 5 cents a piece and free on the curb!
the tubes are usually good but will be destroyed if the power is applied while capacitors are shoted out, replacing the 5 cent capacitors will save the tubes from being destroyed!
TUBES DO NOT STOP WORKING FROM BEING STORED!
ELECTROLYTIC CAPS SHORT/OPEN WHEN STORED 50 YRS!
the tubes are hard to find, and usually expensive, and if they are blown,,, what happens to the ink markings that were on the glass of the shattered tube??? hehe gone.
unknown tube = unknown availability and price
oh and not to distract from Veronica ;) she is pretty and i think ready for work(code)
i love seeing how she(it) migrated from breadboards to a (solid, pun intended) working unit. so many SBC’s end up a pile of useless (unfinished) circuitboards.
so many SBC’s have been attempted and given up on im glad to see someone has completed one, even in this modern age of $2 uC chips.
Needs some nixies in place of those LED displays. :)
+1
+1 to that
Has anyone seen hexadecimal nixie tubes? If so, I’d love to try putting some in there.
There are 7 segment nixies available such as the Rodan MG-17 series.
Haven’t seen hex nixies but:
1) octal FTW
2) VFD and Numitrons are also okay :)
Cool- I’ll have to look into those.
Thanks for the post HaD! Just to clarify, the display you see in the lower slot is temporary. I have a few ideas for what to do with that space.. Same goes for the spot where the old knobs were. So many projects, so little time…
I would recommend to replace the LED hex digits with numitrons. You would need to think about the right way to drive them (they need something like 50mA per filament), but the old stylish orange glow would fit the housing perfectly.
I am planning to equip an old radio receiver with modern guts (MP3, WiFi and stuff), but the display will be made of tiny incadescent light bulbs. I might drop a magic eye in as well…
Yup, much easier than Nixies as the Numitrons run on 5VDC, not 180VDC.
Quinn; I have an idea regarding the three holes in the front of the case.. I don’t know if you’re ever planning on getting this project to a point that it would accept a keyboard/monitor, but “80’s” computers used round DIN connectors for things like that. Commodore, for example, used a 5pin DIN for the monitor, for the disk drive, the power supply, etc.., so, they were pretty common.
I could see this box with 3 connectors up front for Keyboard, Monitor, and External expansion. Or MIDI.
Ah yes, I remember those connectors well. Good idea! I would like to do a keyboard or other input device at some point.
If you rewired the connectors of USB Keyboard, etc, into DIN connectors that would be prefect.
If you are willing to do some digging and work with high voltages, a panaplex display might be perfect for this thing. If you salvage the panaplex display from a Monroe or Compucorp 300 series portable calculator (early 1970s) you can find a 16 digit 7 segment neon gas display with a visual area that’s only .25 by 4.25 inches!