KIM Uno update: KIM-1 & Apple-1 in Arduino/esp32/STM32

[oscarv]

I just updated my KIM Uno, a little ($10 in parts) pocket-sized KIM-1 'replica' of a few years ago. The code now also runs on the STM32 Blue Pill & esp32 microcontrollers. And on the TT-GO 2020 smartwatch, for no particular reason.

A picture is quickest to explain what the update is intended to do:


The software can run on a 'bare' microcontroller (just using a serial port), or make use of my KIM Uno PCB to become a stand-alone battery-powered 'Pocket KIM'.

I was inspired by Marcel van Kervinck's Apple-1/Gigatron hackery, and Mike Barry's Apple-1 port of the mini-assembler in that thread. So the KIM Uno is now "Apple-1 compatible". It was mostly adding the Wozmon/ACI ROMs and 4 I/O ports. Miraculously, KIM-1 and Apple-1 ROMs are not at all in each other's way. So you can flip from KIM (hex programming) to Apple (mini-assembler programming) and back when playing with 6502 code. It's fun. Two in one.

This update also uses the EEPROM as a solid-state cassette tape. So you can save your work whilst on the road.

As the space in the Arduino's atMega328 is well and truly exhausted now, I'll use the two 32-bit MCUs to continue playing in the future. But I'll miss the cramped atMega328, it fits the KIM-1 simulation like a glove and fighting for free bytes is a nice part of the hobby. On the 32-bitters, there's plenty of room to run much more 6502 software, but my main interest is these sub-1024 byte 'software gems' that are small enough to read & study.


Now and then I make a batch of KIM Uno's (not for profit). But you might as well send off the KIM Uno Gerbers to JLCPCB.com (or somesuch) yourself and order the few other parts online on Aliexpress etc. The Pro Mini plugs right in to the PCB; the STM32 and esp32 have to be wired in. I'll make a new PCB version soonish to hold the 32 bitters without wiring hassle.



The updated web site with all data is here: https://obsolescence.wixsite.com/obsole ... mary-c1uuh

Credits: Marcel van Kervinck, for having been an inspiration in everything he did. Mike Barry for that wonderful mini-assembler post, and of course Mike Chambers again for his 6502 simulator. I just glue stuff together, but I hope it'll provide fun to others as well.


Kind regards,

Oscar.

[BillG]

Though I have not gotten around to it yet, I still intend to hack one of the KIM Uno I bought into a Heathkit ET-3400.

[oscarv]

BillG wrote:

Though I have not gotten around to it yet, I still intend to hack one of the KIM Uno I bought into a Heathkit ET-3400.

That would be fun - Al Williams already made a Cosmac Elf (1802) for it, the 6800 would complete the trilogy.

Kind regards,

Oscar.

[okwatts]

I can vouch for the beauty of this little beast. Its very handy to compare to the real KIM (sitting in a drawer). I have also loaded the software on a STM32 Blue pill and this gives a lot more memory. Now I just need to get an ESP32 for the max memory and storage. It would be great to see a SYM-1 version but that would require another row for the extra keys, also I need to add the Graphics display from the ELF1802 version to see what might be possible for the KIM.
Thanks again for keeping this going with the new software and alternate microcontrollers.

Larry

[BigEd]

(Welcome, Larry!)

[oscarv]

Nothing beats a good lockdown to make progress on the successor of the KIM Uno.

Here is the prototype "ESP65" in KIM-1 mode, cased with its optional fold-up display.
As my Christmas location does not offer a box of screws, the panels sit loose in the case. But never mind. Those are details.




Here is the machine in its "desktop" Apple-1 mode, with the matching Bluetooth keyboard for those few moments when 6502 hex-coding is not sufficient:



As an option, you can also swap the ASCII and hex keyboards, so you end up with a mini-terminal plus handheld KIM-1 'remote'.

With lots of space in the esp32, the next step will be to get a proper 6502 operating system, DOS65, running.
That completes my purpose with this project: experience the 6502 from early hex pad programming, via the added ASCII comforts of the Apple-1, through to a 'desktop' with proper operating system.

To be continued!

Kind regards,

Oscar.

[BigEd]

Splendid!

[GARTHWILSON]

Congratulations, particularly on the packaging. Good packaging on hand-held units is difficult to accomplish. I know from personal experience. It's also why laptop computers have been so much more expensive than desktop computers with the same capabilities.

[okwatts]

Looking forward to the "finished" product. Sign me up for one of your kits when they are ready!

[oscarv]

Update... I've progressed to bring together KIM-1, Apple-1 and the DOS/65 operating system so they work together. It still leaves 32K for regular DOS/65 programs, and as the DOS/65 bootstrap only takes 75 bytes of ROM, almost all 64K space is free for KIM-1 and Apple-1 software. Which DOS/65 can load from disk. Lots of 6502 software gems still to port and bring up. The first is Dan Werner's full-screen editor SEDIT, but making a VT-100 compliant terminal is nontrivial, as I am finding out.

The standard variant looks like this, showing how it steps from Apple-1 Basic to DOS/65, where the vastly superior ehBasic is running as well. Hardware cosmetics will be improved for prototype 3 in about a month:




It's become a modular family of components: hex programmer's panel/CPU, ascii keyboard/CPU and display unit. Mix and match as you like, keypad and keyboard connect wirelessly:



I will upload Kicad and firmware after the next update, when they are in a somewhat presentable form.

Kind regards,

Oscar.

[okwatts]

Looking good and looking forward to the details. Thanks for sharing and making another addition to the 6502 legacy.

[tingo]

The ESP65 looks very nice!

[okwatts]

Hi Oscar just poking to see how things are progressing with ESP65