Recent content by jltursan

Yep, it really needs a mkII, I only known of a "Mario Bros" for the plain PC-8001; but not the "Special" release...

I think that a 28C64 could be a better replacement for the old 2764. Probably easier to find and being electrically erasable, easier to program with a common EPROM programmer like the new XGECU T48, this one is my recommendation, the successor of the well-known TL866II Plus.

Reflow C3 soldering just in case; if nothing changes, replace it, seems to be a bit flaky.

I've found quite some Dragon machines with busted 6809 CPUs; but usually more "at" chars appears on screen. Also, there's a 10K variable resistor with vertical mount that also gets some strange debris, like crystal and causes screen havoc similar to the one you posted. The resistor is located...

Welcome!, nice to see you here :)

For $80 it's a bargain indeed! And yes, it's more collectable than practical if you already have 4A machine. The built-in VDP was the first of the series and more limited than the common TMS9918A.

Congrats!, they're pretty rare (at least compared to its big A brother). Nice find if the price was right (y)

Gaming Alexandria has recently added a new Type-in entry for the JR-100: Grade Average Bar Graph I'm eager to see that tapes preserved!

Btw, here's the Aquarius power inputs schematic:

Check comment of the above video

As per the info found in this page, the PSU just provides the unregulated voltages for the +12V, +5V and -12V needed internally. Here someone is replacing its PSU with a new one: I think you can buy the above here (I'm not related to this seller ;)) ...but I'm sure you can mod it to have an...

Great, that's cool!. The WD2793 need some calibration before using it, right?

Nice machine, isn't it? ;). Well, maybe a bit bulky if you have some expansions connected...

Not too much; but here you've a sheet with a lot of hardware info.

Nice machine!. Does you barebones (=no extra graphics cards) MZ-80B works 100%?, just my two cents...