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MP-S Connector for SWTPc 6800

by billdeg
Total messages in this thread: 1
Molex connector SWTPc MP-S for RS232
Close up view of the correct wiring for an SWTPc MP-S serial card set for RS232 communications. Click image for larger view.
Note Molex pins 2 and 3 are jumpered together, and so are pins 7 and 10. The bottom of pin 4 has been snipped off to ensure correct insertion into the MP-S card. Wiring for pins 1,5,6 is mapped below. Note also the colors of the wires. Connector from SWTPc MP-S to RS232 adapter
Closeup of the wires coming from the MP-S connector to an RS232 jack. Click image for larger view.
MP-S Pin RS232 Pin 1 ........ 7 2 ........ - 3">... [ read more ]

SWTPc MP-09 6809 Processor Card

by billdeg
Total messages in this thread: 1
SWTPc MP-09 processor card upgrade for the 6800 computer. Click for larger view
Recently I put an extra SWTPc 6800 with MP-09 processor card, MP-S serial card, and Smoke Signal Broadcasting M-16-X 16K RAM card on Ebay. Assuming the system sells, at least I will have the photos of this system. I learned a lot of about the differences between the 6800 and 6809, and the modifications necessary to the MP-B motherboard, etc. RAM cards from a 6800 usually need to be altered to work in an 6809-upgraded system. The Smoke Signal Broadcasting card appears to be at least partially compatible with no modifications, as compared to the older MP RAM from the original SWTPc 6800.">... [ read more ]

Apple IIe Platinum

by billdeg
Total messages in this thread: 2
Updated: [ Apple IIe A2S2128 ] 06/19/2013
In 1987 the Apple IIe was revised. This system works but has some broken keys on the numeric keypad.
This particular unit contains an Echo IIb sound card and external speaker with volume control. More Pics">... [ read more ]

Collectible Micro Sleepers List Updated

by billdeg
Total messages in this thread: 4
Updated: [ Collectible Micro Sleepers List Updated ] 06/07/2013
In response to the article published in PC World titled "The Most Collectible PCs of All Time" http://www.pcworl...oppcs/article.html I don't disagree with the list, but yawn...another rehash of the "standard" stuff we have all been hearing about for the past 5 years. It's because of these articles, at least in part, that they're so popular for collectors. A cycle of re-inforcement. Being a kind of anti-establishment fellow, here is my personal Top 10 or so list of sleepers - classic computers that are less well-known but very rare and collectible. Would I rather have an Apple I or a Kenbak? ..yah, but I'd like some of the below just as much...and they're much cheaper! 1. Micro Altair (later called Poly-88), by PolyMorphic Systems MITS forced Polymorphic to change the name of their computer to Poly 88 2. BYT-8 (or -5), by Byte C">... [ read more ]

TSC BASIC for SWTPc 6800

by billdeg
Total messages in this thread: 2
Updated: [ Load TSC BASIC on SWTPc 6800 from Laptop ] 06/04/2013
It took more than three hours entering in almost 4Kb worth of 2-digit HEX instructions into my teletype, and a good 20 minutes or so to punch a tape, but I was successfully able to save TSC BASIC on my SWPTc 6800 to papertape. And the freakin thing actually worked the first time. The documentation for TSC BASIC told me how to modify the program for my system, etc. Saving me a lot of debugging time. There is a write up about TSC BASIC in the January 1978 Kilobaud (comparing 4 6800 CPU BASICs), and fortunately I found a copy of the papertape program here: http://www.swtpc....c/TSC_MicroBasic.htm I downloaded the papertape program as a text file and then parsed the data in MS Excel. This way I could separate the data from the checksum at the end of each line of papertape, and to see the address value. There is a point when entering in t">... [ read more ]

Handic CBM BX700 Cartridge Software

by billdeg
Total messages in this thread: 2
Updated: [ Comment from former Handic Employee ] 06/01/2013
In 1983 the Sweedish company Handic produced software for the CBM BX700 called Calc Result (spreadsheet) and Word Result (word processor). There were also versions of this software made for the C64 model.
Now that I have successfully installed and tested the 8088 co-processor, I thought that I would next try the Handic software supposedly made for the BX700. The "X" indicating the presence of an 8088 co-processor. This is probably a rare software because there were few BX700's sold in Europe, and the software would have seen limited sales as well. I was able to run both the Calc Result and Word Result software cart/disk programs. I am not sure if the 8088 was required, I only tested on a system with the add-on board installed. pictures">... [ read more ]

1955 GENIAC Computer

by billdeg
Total messages in this thread: 1
cir. 1955 Geniac Kit with Accessories
circa. 1955 GENIAC computer kit with accessories. Note that this box contains nearly two kits (two boards, two sets of discs, etc). Click for larger view.
Back cover of Geniacs booklet
Back cover of Geniacs booklet. Click for larger view.
GENIAC program discs
Note how program discs had different spacings. Click for larger view.
More photos and PDFs NEXT: As">... [ read more ]

Drive Alignment C128D Internal 1571

by billdeg
Total messages in this thread: 1
I picked up a C128D with a non-functioning internal 1571 disk drive. Using a copy of 1541/1571 Drive Alignment loaded from an external 1571 drive (logical drive 9), I was able to guess my way through the process, given the directions do not cover the internal 1571 of the C-128D. You can read more how-to from the manual, the closest example is the "newer" external 1571 described on page 7. Note the 4 screws at 12 o'clock in the photo above. The two that are closer together are the stepper motor adjustment screws and they control how far back the stepper motor goes. I made minute adjustments until the program passed the Bump test with an "excel">... [ read more ]

MARCH Spring Workshop

by billdeg
Total messages in this thread: 1
Evan K working on an Osborne I portable computer. Also pictured is MARCH's PDP 11/20 (on its side). Click Image for larger view.
The first MARCH event since Hurricane Sandy was an "open house" swap meet and workshop (the Vintage Computer Festival was cancelled). Most of us brought items to sale or trade, and we also brought projects to work on. Around 7:30 we all went out for dinner and then returned for more hacking. The event continued the next day but I had to leave around midnight.
Photo of a C-64 Ethernet">... [ read more ]

CBM KIM-1 Rev G Restoration

by billdeg
Total messages in this thread: 4
Updated: [ Photos Commodore KIM-1 Rev G ] 08/27/2014
Started project to restore a non-functioning Commodore Kim-1 (Rev G). Working with a number of attendees at the Spring MARCH workshop we concluded that the 6502 socket was bad. I also replaced the dual timer chip in U25.
More to come.">... [ read more ]

Motorola MEK6800D2 Microcomputer

by billdeg
Total messages in this thread: 3
Updated: [ Motorola 6800 JBUG Monitor ] 04/25/2013
1-10-05 Pictures htt...otorola/mek6800d2/ I have not yet tested this single board computer. I have the manual, it's very good, should be fun. Requires a 5V DC @ 2.5 MA. I have to splice up an adapter, etc. ">... [ read more ]

B 128 Alternative OS Expansion Board

by billdeg
Total messages in this thread: 1
The Anderson Communications Engineering Alternate Operating System Expansion Circuit Board for the Commodore B Series computer
More to come!">... [ read more ]


by billdeg
Total messages in this thread: 12
Updated: [ RCA 1800 Family Oral History Panel ] 12/21/2018
The 1974 RCA COSMAC Microkit. This is the first commercial microcomputer from RCA to contain the two-chip COSMAC microprocessor (TC 1084 / TC 1085 version). The processor was developed in New Jersey, but the kit itself came out of the RCA Palm Beach Division. Click image for larger view.
RCA COSMAC 3901822
Note the TC 1085 chip on the processor card, which is the earlier name for the CDP 1801 and has a silk screen date of late 1974. Click image for larger view.
Compare the above processor c">... [ read more ]

Intersil 6100 PDP 8 Homebrew System

by billdeg
Total messages in this thread: 1
Took a few photos of a homebrew Intersil 6100 PDP 8 Homebrew computer built by William F. Dudley Jr. which he donated to MARCH.
More photos I did not get a chance to photograph the ROM card (need to download the 2708 ROMs) nor the processor card. The front panel is a primitive four-digit octal dial. Here is a thread from Mid-Atlantic Retro message board: William F. Dudley Jr. donated another wonderful box of homebrew parts to MARCH: a new unused Intersil 6100 eval kit, several PHI-deck digital cassettes (2 in the original blue eval cases), spare memory cards and schematics. The intention was to build a PDP8 using the 6100 chips and the PHI decks emulating DECtapes to run OS8 and all the PDP8 software. Each memory card is 4k of 12 bit DRAM, 8 max per system. ">... [ read more ]

Trenton Computer Festival 2013

by billdeg
Total messages in this thread: 1
Mark 8 Minicomputer display at Trenton Computer Festival 2013
Who wouldn't be smiling if they had a beautiful Mark 8 to feature at their computer exhibit? MARCH is proud to have received (on loan) an original Mark 8 computer for our computer museum. The system came to us from David Larson curator of the BugBook Museum located in Floyd Virginia. The Mark 8 was designed by Dr. John Titus and this particular Mark 8 was built by George Overfelt in 1975. The Mark 8 will be displayed within the MARCH vintage computing exhibit within the Infoage Science Center in Wall, NJ. Click image for larger view.
Herb Johnson Heathkit H8 Tren... [ read more ]
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