9815 Test ROM 98140-66501 ?

[artag]

It's also mentioned in the source code in the 9815 patented indexed on Eric Smith's site : notably in the fitst few instructions

LDS #ISTACK ; INITIALIZE STACK POINTER
LDA A, $1002 ; GET POSSIBLE TEST ROM
CMPA #$39 ; IS IT THERE ?
BNE NOTEST ; BRANCH IF NOT
JMP $1025 ; ELSE LET IT HAVE CONTROL

So a ROM decoded at $1000 having $39 (ascii 9) at offset 2 and an entry point at offset 25 will be executed with no dependency on RAM or any other i/o.

This could be something like a 98136A with nonstandard address decode and a special rom - this would then allow test/debug over the serial port.

Some other useful information would therefore be usage notes for the test rom. It wouldn't be hard to write a functional replacement. In fact an off-the-shelf 6800 rom monitor such as SWTBUG, perhaps with a few 9815 specifics such as ram and peripheral tests would probably do most of what's wanted for enthusiasts.

There's relatively little internet activity regarding the 9815 - nothing like the excellent 9825, 41 or 71 resources. But I keep coming across occasional individuals who have them, and its status as the last RPN desktop or the first industry-standard processor stands out a little. Who else has one in their collection ?