I bought this Japanese Altair clone <https://deramp.com/downloads/mfe_archive/010-S100%20Computers%20and%20Boards/00-Mac8/20-Mac%20Systems/Mac8%20EMIC%20Alpha%20S-100/Photos/> some years ago. According to the seller, it never worked right. He suspected that the problem was the 100VAC versus 120VAC that's in some parts of Japan.
I found that it did work a little better with reduced AC voltage, but it never worked right at all. When I dug into it, I found that Vcc on the front panel was about 7V! Looking closely at the front panel's regulator, I noticed that the outline on the silkscreen was drawn with dotted lines. As I suspected, this indicated that the regulator and its heatsink were meant to be mounted on the solder side of the board. But they were mounted on the component side! Turns out that a 7805 kinda-sorta works if its output and input are swapped :-) I removed it and mounted it on the solder side, and the machine now works like a champ. 100VAC, 120VAC, either way. All of the front panel components survived this overvoltage, and the 7805 was fine. I can understand how the seller got this wrong - the manual and schematic are entirely in Japanese. He told me that he bought the machine around 1980 as a kit in Japan, and assembled the boards (not including soldering) on the plane ride home. Imagine that in today's high-security environment! Martin E. On Mon, Nov 24, 2025 at 11:51 AM Santo Nucifora via cctalk < [email protected]> wrote: > I have the self-titled "Bill-1" 8008 based computer made up of boards from > Litton Data Systems. I haven't looked at it in years but now that I have a > little more knowledge in vintage computing, I'll have to take a look at it > soon and see if there's anything I can get going. > > https://vintagecomputer.ca/the-bill-1-8008-based-computer/ > > On Mon, Nov 24, 2025 at 2:33 PM Adrian Stoness via cctalk < > [email protected]> wrote: > > > that helps as i know nothing about this machine > > > > On Mon, Nov 24, 2025 at 3:41 AM Henk Stegeman via cctalk < > > [email protected]> wrote: > > > > > Looking at the date stamps on the chips late 1976 > > > > > > On 11/24/2025 10:16 AM, Adrian Stoness via cctalk wrote: > > > > ive got this motorola 6800 system from about 1975 > > > > https://live.staticflickr.com/65535/50199901793_f074af16c0_b.jpg > > > > https://live.staticflickr.com/65535/50199903443_7c7caa4228_b.jpg > > > > https://live.staticflickr.com/65535/50200713557_6d8270d128_o.jpg > > > > > > > > > > > > On Mon, Nov 24, 2025 at 3:00 AM Henk Stegeman via cctalk < > > > > [email protected]> wrote: > > > > > > > >> A diy TTL system build in 1976 > > > >> > > > >> http://www.ibmsystem3.nl/hjs22/ > > > >> > > > >> (Click through the security warnings) > > > >> > > > >> On 11/24/2025 5:13 AM, ben via cctalk wrote: > > > >>> Who has strange or one of a kind computers out there? > > > >>> I have a 18 bit homebrew (cpld) with 256Kb ram and just a bootstrap > > > >>> loader. > > > >>> > > > > > >
