On Tue, Dec 29, 2020 at 10:33 AM Jameel Akari via vcf-midatlantic <vcf-midatlantic@lists.vcfed.org> wrote:
On Tue, Dec 29, 2020 at 02:44 Ethan Dicks via vcf-midatlantic < vcf-midatlantic@lists.vcfed.org> wrote:
... On the bench, I just received (after 2+ months of waiting) some edge connectors to finish constructing the memory/expansion board for my SYM-1...
I was surprised on how expensive those card-edge connectors are.
They were not cheap back in the day ($3.50 or more 30 years ago). I got some cheap Chinese ones and they are indeed cheap. The pins on the solder-tail connectors are slightly migratory. I tacked down the corner pins first, as one does, and out of 6 connectors, one pin raised slightly out of its slot and I get to unsolder, reseat, then solder it back.
OTOH, I haven’t managed to come up with anything to do on my SYM-1 that strains the 4kB on-board or needs more I/O than it already provides.
The expansion board comes with pads to attach an SD interface and the ROM socket lets you load up SYMDOS that can use pins of a VIA to talk to a Commodore 1541. Once I get all that working, I have plans for something that will easily soak up 32K. It was something I wanted to do for the last VCF East but didn't have time to do the expansion for. My SYM lacks BASIC ROMs, which this expansion also includes. Those would be easy enough to burn on their own, but now, it's just included as part of the larger package. The expansion also includes DC-DC converters for running the entire machine from a 7.5VDC PSU and for providing negative voltage for the serial interface, but those features were not important to me. I'm after the 32K RAM expansion, the single large ROM socket, and the pads for the 1541 interface. Even with $20 in cheap edge connectors, having all that on one expansion board is kind of handy.
Meanwhile I still have the Lego Saturn V from last xmas to build…
I built mine last year. This year I got the LEGO ISS. -ethan