User avatar

Posted Fri Apr 24, 2020 11:59 am

Doesn’t work, tried that :).

An example: the driver for the Melody 1200 checks for the pcmcia device in RAM. Unfortunately, that is only in RAM if there is the respective hardware...

User avatar

Posted Sun May 10, 2020 9:09 am

Back in 1986/1987, my friend, Jim Rothrock and I made a battery backed up real time clock called LittleBen which plugged into the second mouse port.

Jim wrote the software and I designed and built the hardware. I think we sold about 30 of them. They were all hand built. It was my first experience in running a business - IIRC, we broke even on the hardware but didn't make enough money to pay Jim for writing the software. I designed the circuit, printed circuit board, had them manufactured, called around and got quotes for all the parts, ordered the "best deal" - back then shipping was like $2.xx for a package! Then, I hand assembled them. This was the most challenging part because it was a lot of soldering and doing it at home without a great workbench was difficult. Then, I had to let them run for a little bit so that I could fine tune the frequency so that they didn't gain or lose time, make sure the battery was charging and holding charge, etc.

I did the hardware development on an Atari 800 using Action! (!_( ... _language)) since I was more familiar with that setup than my Amiga. Jim looked at it and ignored it and wrote his own version.

Inside, it had a Signetics chip (now NXP), a NiCd battery which was charged from the port, a variable capacitor to trim the frequency and a couple of other resistors, capacitors and I think a diode (for charging).

I've attached a picture of the manual, hardware unit, and the chips that were in it.

User avatar

Posted Mon May 11, 2020 9:16 pm

Thanks for sharing. You used the same RTC chip that Microbotics used in the Stardrive and Multifunction Modules for the Starboard 2.
Maybe also in the MouseTime.
I hadn’t seen that chip being used much, but then again the Oki and Ricoh Chips used with the later Amiga models are probably also not that common.

Return to “Hardware”