SDC_Zero 65C02 - a minimalistic 6502 computer

[gbm]

I finally found some time to complete the simplified, low cost offspring of my SDC_One design. Some facts and photos:

SDC_Zero Software-Defined Computer
- a minimalistic 65C02-based computer

Features:
• hardware monitor with single-stepping, disassembly, memory editing and drag-and-drop HEX file loading
• 16 KiB RAM, 64 KiB ROM (easily programmed using h/w monitor)
• terminal (console) interface for 6502
• timer and single LED for 6502
• Power supply, h/w monitor communication and target computer terminal via USB double VCOM device

Assembly time: 30 min

Components - total cost: < 8 USD
• „830” type breadboard
• ca. 40 male-male jumper wires
• one female-male jumper wire
• 1..2 pcs 100 nF through-hole ceramic capacitor
• one 10 kOhm through-hole resistor
• 65C02 CPU
• „BluePill” board (STM32F103C8T6 Minimum Development Board)

Binary form of STM32 firmware available on request

[whartung]

Do you have more about the theory of operation on this?

[gbm]

That's my own design, so I actually have everything regarding the theory and practice. There are also few articles available (3 in English), just google for "SDC_One Software-Defined Computer".

You may also look up my previous posts on SDC_One (dated Jan/Feb 2018) at 6502.org, anycpu.org and retrobrewcomputers forum.

SDC_Zero is a simplified, DIY extremely low-cost version of SDC_One. Another version of SDC_Zero uses the 80C85 or 8085 CPU.
I plan to publish the details at GitHub. Not sure about full firmware sources, as the USB stuff is quite precious. Maybe I'll put the USB core into a binary-only library and the rest (including the CPU logic) will be published in source form.

[Michael]

gbm wrote:

Binary form of STM32 firmware available on request

I would love to try this. Can I use my ST-LINK V2 to load the firmware, and, is there a connection diagram/schematic somewhere, please? Also, is the comparable speed still somewhere in the several hundred kilohertz range?

TIA... Cheerful regards, Mike, K8LH

[gbm]

Description and assembly instructions are attached in .pdf file. Let me know if anything important is missing.

[BigEd]

(bump!)