Recent content by Alegend

Hi mpiazza, Your issue is simply the burnt out 74AC14. Replace it and you will be fine. The very basic DCOK and POK power up analog delay circuit is not my invention and it works well. When assembled correctly (no R13 R16) the two LEDs are OFF during normal operation, not ON. QBUS signals may be...

Dear mpiazza, Finally perhaps you will read my repsonse, sorry it has to be with all the world to see, but you do not seem to be someone who opens the inbox or reads messages. Ever. 1. On 3-OCT-2024 I have received a message from you requesting information about building a number of supplies...

No, unfortunately I don't have any. But all the production files are on GitHub. So you can have a bare PCB made and delivered for less than the cost of a half priced pizza.

Well obviously you need to study the properties of different magnetic media (such as coercivity and maximum flux density), obtain some suitable old media that are not as bad as the one you're trying to replace, carefully spool 600 feet of said media on a carefully disassembled TK50 cartridge...

It *is* a possibly dumb idea.... To quote Bill Bailey, it sounds like "a long walk down a windy beach to a café that was closed" Alon.

It is running off a very real SanDisk 16GB MicroSD card, in a SCSI2SD.

Well, today of course is Wednesday which is also May the 14th - the 40th anniversary of the introduction of the MicroVAX II minicomputer from Digital Equipment Corporation. It was headline news at the time: “DIGITAL’S BID FOR A COMEBACK”, New York Times, May 14th 1985 “MicroVAX II is one of...

Correct my mistake - the part number is for another type. MTA 156 is correct though. The series has its own crimp pins but indeed they appear obsolete even on the TE website... -Alon.

What you need is a TE MTA156 series connector. For example the 18-pin part number is 4-640426-8 . To assemble your own loom you'd need of course the pins, some 18AWG wire and a crimping tool as well -Alon.

Hi All, After going through nothing but 20 years of quiet storage, one of the ceramic ICs on my Webster WQSMD/03 SMD disk controller has decided to split apart. As it is evidently busted, I am looking for a replacement or some other solution to bring the WQSMD back to life. The busted IC is a...

It can be done. The IDC connector can be squeezed in the narrow space, you just need to keep it flat with the surfaces above and below as you push it through, and not diagonal. -Alon.

What is the actual computer or port? Many USB<>RS232 adapters do not generate proper +/-12 Volt signals. Some only give out +/-3 Volts. It works fine when receiving but can fail when transmitting, as the other side may not detect the signals at all. -Alon.

Just use an old IDE disk drive or two as a load for testing. Your BA23 already has the correct loom. -Alon.

Not sure what the original foam was, but a Digikey search under "Raw Materials - Foam" returns hundreds of results, many materials in all shapes and sizes, with or without adhesive. Generally I have found EPDM to be easy to work with and suitable for enclosure sealing etc., and it's pretty...

This board should work as all it needs is a standard "disk drive" 4-pin molex (for the charging IC) and a 2-pin connection going to the main board, similar to the one all battery packs from that era were using (100 mil pitch, Molex KK series). -Alon.