Recently, Michael Steil published a blog post about connecting NES and SNES Controller to a 6502-based system showing how to use NES and SNES controllers on a C64 without the need for any special hardware, by just connecting them to the C64’s user port.

Why not use his approach and adapt it to the Steckschwein? The Steckschwein has a User Port, too, albeit a very different one as the C64. Basically, the Steckschwein-User-Port consists of the complete Port A of the VIA, plus the /RESET and /IRQ lines. Also of course, VCC and GND.

Chuck Peddle, the main designer of the 6502, has passed away on Dec. 15th, 2019.

Peddle was one of the engineers that developed the 6800 at Motorola. He later went to MOS in order to implement his vision of an 8bit CPU for way less than $300, which was Motorola’s price for the 6800.

This idea of a cheap but powerful CPU materialized as the 6501, and finally the 6502. That very chip, which started the microcomputer revolution, and on which both Marko and myself began to write our first code ever at an early age. BASIC at first, followed by assembly language later.

Back from the VCFB (Vintage Computer Festival Berlin) 2019 where we had good talks, met interesting people and got new ideas. Especially from Michael Steil who just asked the simple question “How you can develop software for the Steckschwein without an emulator?”

With the answer in my mind I felt a little annoyed and also “triggered” at the same time… However, Michael Steil was nice enough to strip down his Commander X16-Emulator into a barebone 65c02 computer emulator, so all we had to do was to implement our memory map (easy) and borrow a V9958 video chip implementation from blueMSX and implement it into the emulator (hard).

Marko talked about his Pacman port to the Steckschwein at VCFb. Basically it’s the same talk he did at VCFe in April, but this time, there’s a video. Enjoy!

https://media.ccc.de/v/vcfb19_-_111_-_de_-_201910121615_-_pac-man_auf_dem_steckschwein_-_marko_lauke

Frank van den Hoef, who is adapting the Steckschwein SPI & FAT32 code for his tiny65 machine made me aware of a classic mistake for a 6502 assembly coder to make. Namely in our sdcard driver, when waiting for the “proper” response from the card (which should have bit 7 cleared). The routine handling this looked like this:

1  sd_cmd_response_wait:
2 	ldy #sd_cmd_response_retries
3 @l:	dey
4         beq sd_block_cmd_timeout ; y already 0? then invalid response or timeout
5         jsr spi_r_byte
6         bit #80	; bit 7 clear
7         bne @l  ; no, next byte
8         cmp #$00 ; got cmd response, check if $00 to set z flag accordingly
9         rts
10 sd_block_cmd_timeout:
11        debug "sd_block_cmd_timeout"
12        lda #$1f ; make up error code distinct from possible sd card responses to mark timeout
13        rts

Classic. Obviously, line 6 should read:

The main motivation to get Forth up and running on the Steckschwein was to participate at The Ultimate Benchmark, in order to crush all 8bit competition to dust.

So the plan was to benchmark the Steckschwein live at the VCFe. Unfortunately, Carsten could not be there, so no Forth benchmark competition this year. Recently, Carsten presented his benchmark results using TaliForth2, which led us to run the same benchmarks he did and send the results to Carsten, who was kind enough to include them on his site: