View Profile: thunter0512 - Vintage Computer Forum

Yesterday, 07:47 AM

thunter0512 started a thread PDP-8/E OMNIBUS Ride in DEC

I have stumbled across a really interesting article by Remo J. Vogelsang the lead engineer for the PDP-8/E project. ...

3 replies | 81 view(s)

February 23rd, 2021, 07:18 AM

thunter0512 replied to a thread RX01 floppy drive adventures in DEC

The fans on the Lab-8/e's RX01 are mounted directly on the back of the Calcomp drives. There are two fans - one for each drive. Next to the fan is...

32 replies | 1583 view(s)

February 23rd, 2021, 07:03 AM

thunter0512 replied to a thread RX01 floppy drive adventures in DEC

Hmmm - I see. What is the purpose of the dust filter in the back of the two drives? What kind of engineer designs a system with a dust filter which...

32 replies | 1583 view(s)

February 23rd, 2021, 03:29 AM

thunter0512 replied to a thread RX01 floppy drive adventures in DEC

Now the Lab-8/e rack has a beautiful fully working and relatively "quiet" RX01 floppy drive assembly, the drives are screaming out for a lid. The...

32 replies | 1583 view(s)

February 22nd, 2021, 07:20 AM

thunter0512 replied to a thread RX01 floppy drive adventures in DEC

Finally I have a well behaved RX01 floppy drive subsystem. I bought two new bearings for the top spindle assembly and both drives are now "quiet"...

32 replies | 1583 view(s)

February 16th, 2021, 06:58 AM

thunter0512 replied to a thread RX01 floppy drive adventures in DEC

I have been experimenting with "dry" Teflon lubricant. It is wet when you apply it but becomes completely drive after a short while. The advantage is...

32 replies | 1583 view(s)

February 16th, 2021, 06:23 AM

thunter0512 replied to a thread RX01 floppy drive adventures in DEC

Most drives (or their controller) unloaded the head or stopped the spindle after a few seconds of inactivity. The RX01 appears to unload after every...

32 replies | 1583 view(s)

February 15th, 2021, 07:50 AM

thunter0512 replied to a thread RX01 floppy drive adventures in DEC

After reading the OS8 Language Reference manual I discovered that "ME 30" simply means "Missing END statement" after line 30. Now my little BASIC...

32 replies | 1583 view(s)

February 14th, 2021, 05:27 PM

1944GPW replied to a thread When does BASIC not become BASIC? in Vintage Computer Programming

From the above discussion I was 65% interested in finding out more about the origin of BASIC not covered in the video. That documentary mentioned a...

55 replies | 1169 view(s)

February 14th, 2021, 07:47 AM

thunter0512 replied to a thread RX01 floppy drive adventures in DEC

Hi Roland, Success! I have now reassembled the dual RX01 drive from the Lab-8/e and hooked it up to the M8357 controller with the original...

32 replies | 1583 view(s)

February 14th, 2021, 01:19 AM

1944GPW replied to a thread When does BASIC not become BASIC? in Vintage Computer Programming

Yep that's the book! It was a large quarto size paperback with a blue cover and a green circle on the front. I regret tossing it out some 15 years or...

55 replies | 1169 view(s)

February 13th, 2021, 09:40 PM

1944GPW replied to a thread When does BASIC not become BASIC? in Vintage Computer Programming

Thanks CP/M User, I appreciate you preparing the list of keywords and functions. One of the early books I acquired on BASIC was IIRC 'BASIC for...

55 replies | 1169 view(s)

February 12th, 2021, 11:14 PM

thunter0512 replied to a thread RX01 floppy drive adventures in DEC

After reforming the two large capacitors on the RX01 drive I powered it up without any logic connected and found the voltages to be on the high side....

32 replies | 1583 view(s)

February 11th, 2021, 08:31 AM

thunter0512 replied to a thread What did I do to my PDP-8 today. in DEC

Today I finally pulled apart the dual RX01 from the LAB-8/e rack. After further cleaning it and applying some teflon spray to the lead shaft and the...

206 replies | 14325 view(s)

February 7th, 2021, 02:36 PM

1944GPW replied to a thread Looking for digitalker ROMs or ROM Images in Vintage Computer Items Wanted

Glad you've found at least part of what you're looking for. Back in the early 80s I had the loan of an S-100 Digitalker card, which I tried in my...

3 replies | 179 view(s)

February 5th, 2021, 07:57 AM

thunter0512 replied to a thread VT320 - Replace CRT with LCD? in DEC

Most likely is is the CRT itself. The vacuum is not perfect and over time the heater/filament decays and the cathode is poisoned by remaining stuff...

17 replies | 783 view(s)

February 5th, 2021, 07:10 AM

thunter0512 replied to a thread What did I do to my PDP-8 today. in DEC

I hope this Intersil/Harris based PDP-8 is on-topic enough for the hardcore members. :-) My SBC6120 with its FP6120 front panel did not quite...

206 replies | 14325 view(s)

February 4th, 2021, 11:41 PM

thunter0512 replied to a thread What did I do to my PDP-8 today. in DEC

Thanks Doug. I misunderstood and thought this would already work with my existing SerialDisk setup using Kyle's disk images. Toggling in the...

206 replies | 14325 view(s)

February 4th, 2021, 09:51 PM

thunter0512 replied to a thread What did I do to my PDP-8 today. in DEC

Hi Doug, Just to be 100% sure is your boot loader meant to be for SerialDisk? If I read the code correctly it works by depositing 035 words...

206 replies | 14325 view(s)

February 4th, 2021, 05:30 AM

1944GPW replied to a thread Reality check - PDP-8/F on Ebay in DEC

The 11/15 has the KC11 CPU. Very similar but only one level of interrupt. Mine has an extra flip chip to bring it up to four level interrupt, and...

25 replies | 1024 view(s)

February 4th, 2021, 02:06 AM

thunter0512 replied to a thread VT320 - Replace CRT with LCD? in DEC

Why not just emulate the entire VT320 with a small microcontroller and just keep the case?

17 replies | 783 view(s)

February 3rd, 2021, 08:12 AM

thunter0512 replied to a thread Build your own PDP 8I, Part 4.. in DEC

Hi Dave, How are you going with the PCB design? Are you using KiCAD or Eagle? I started browsing through the Prosser book and it looks pretty...

255 replies | 33399 view(s)

February 3rd, 2021, 01:47 AM

thunter0512 replied to a thread Reality check - PDP-8/F on Ebay in DEC

Roland, In now way was my post meant to diminish your great work with the replacement boards. I think you and Vince and others have done some...

25 replies | 1024 view(s)

February 2nd, 2021, 10:46 PM

thunter0512 replied to a thread Reality check - PDP-8/F on Ebay in DEC

Doug, Here is the Epay listing I talked about: https://www.ebay.com/itm/164663937395 Clearly the buyer did not make a rational assessment of...

25 replies | 1024 view(s)

February 2nd, 2021, 09:12 PM

thunter0512 started a thread Reality check - PDP-8/F on Ebay in DEC

A PDP-8/F with minimal configuration (CPU and 8k of core but not even a serial board) just sold for US$8,100 on Epay. There are obviously people...

25 replies | 1024 view(s)

February 2nd, 2021, 08:14 PM

thunter0512 replied to a thread PDP-8/m Interest/Price Check (Canada) in Vintage Computer Items For Sale or Trade

Some people on Epay are crazy. More than 300,000 PDP-8 machines have been produced so these are not a rare by any means. Compare the $8,100...

9 replies | 540 view(s)

January 30th, 2021, 04:15 PM

1944GPW replied to a thread What did I do to my PDP-8 today. in DEC

I'm thinking some of these would be good to get and put aside for my 11/15 some day. I've had a look for the CM7371's on eBay, but not found any as...

206 replies | 14325 view(s)

January 30th, 2021, 09:11 AM

thunter0512 replied to a thread PDP-8 core memory troubleshooting in DEC

The LAB-8/E's 8k core memory boards were originally in the following order viewed from the front: G111C sense/inhibit H212 the actual core G233E...

71 replies | 4495 view(s)

January 30th, 2021, 08:31 AM

thunter0512 replied to a thread What did I do to my PDP-8 today. in DEC

Now I am so glad that I have been working on a LAB-8/e without that built in arm that keeps smacking you in the back of your head. :-) :-) ...

206 replies | 14325 view(s)

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thunter0512
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