2026-05-30 14:15:41 <Stalevar    > MrMobius, so did you figure MK-61?
2026-05-30 14:19:17 <MrMobius    > Stalevar: nah. that's a project for another day
2026-05-30 14:19:31 <MrMobius    > working on building a calculator with an 8051 now
2026-05-30 14:21:03 <Stalevar    > Interesting. Is 8051 similar to 8080?
2026-05-30 14:24:17 <MrMobius    > I don't think so. I don't know 8080 or Z80 well
2026-05-30 14:25:08 <MrMobius    > 8051 is less capable in a lot of ways. it's a microcontroller architecture so good at twiddling bits but needs an 8 bit pointer to access the 128 bytes of RAM after the first 128 and a different 16 bit pointer to address external RAM
2026-05-30 14:25:19 <MrMobius    > 8080 is much more regular afaik
2026-05-30 14:25:27 <Stalevar    > MrMobius, I have an idea of a device. Imagine a calculator, a pocket or desktop one, but with hex keyboard, digits A-F could duplicate buttons like + - × ÷ √ = (or enter, if we use RPN). Then sets of buttons with functions similar Altair or IMSAI control panel: Read / Write, addr+ / addr-, reset, run, stop, step, power on/off.
2026-05-30 14:25:52 <MrMobius    > great idea. you could totally do that
2026-05-30 14:26:25 <Stalevar    > In calculator mode it's like a regular calculator, while in code mode it can use same 7-segment display to display and edit address and data. So programmable calculator but using machine code directly
2026-05-30 14:27:39 <Stalevar    > MrMobius, mainly I am wondering how feasible would it be to have such device under $10, given that it has similar hardware to medium range calculators which are incredibly cheap
2026-05-30 14:28:28 <Stalevar    > Or did everybody lose interest in machine-code-programmable calculators after USSR was gone?
2026-05-30 14:29:19 <Stalevar    > MK-61 or 52 are cool, but super-limited memory of 105 bytes and key-sequence input while display is still in opcodes is weird
2026-05-30 14:32:08 <MrMobius    > Stalevar: depends on your goal. not sure about manufacturing it for $10 but if you just want to build one for yourself, you could do it for around $10
2026-05-30 14:32:54 <MrMobius    > 7-segs look cool so you can do that if you like but it's easy to use a $1 LCD
2026-05-30 14:34:33 <Stalevar    > MrMobius, I'm not so sure in my soldering skills and schematic understanding. I could probably assemble a kit or something, but I'm not so sure about designing anything myself
2026-05-30 14:35:10 <MrMobius    > Stalevar: if 12x12 is not too big for keys, you can use these https://l1nk.dev/4rmjiqx
2026-05-30 14:35:38 <MrMobius    > there are at least 2 calculator kits ive seen but no machine code or anything iirc
2026-05-30 14:35:58 <MrMobius    > hmm, ok. maybe a dev board wired to a hex keypad
2026-05-30 14:36:18 <MrMobius    > although it would be an easy thing to solder if youre interested in learning how :)
2026-05-30 14:37:20 <Stalevar    > I can solder if I got parts and board
2026-05-30 14:38:09 <Stalevar    > But I am not good in understanding what electronic thing is supposed to do by looking at scheme
2026-05-30 14:38:14 <MrMobius    > get some protoboard. very cheap on aliexpress
2026-05-30 14:38:24 <Stalevar    > https://habrastorage.org/webt/0w/m9/g6/0wm9g6akgcfptnb74gfxakbmqwa.jpeg
2026-05-30 14:38:33 <Stalevar    > MrMobius, breadboard? I have some
2026-05-30 14:38:52 <Stalevar    > Or you metal board with holes?
2026-05-30 14:38:56 <MrMobius    > that schematic looks familiar
2026-05-30 14:38:59 <MrMobius    > metal board with holes
2026-05-30 14:39:10 <Stalevar    > I might have those too somewhere
2026-05-30 14:39:22 <MrMobius    > you need about 4 wires from a microcontroller to drive an LCD
2026-05-30 14:39:38 <MrMobius    > and depending on how you set it up, one pin per row of buttons and one pin per column
2026-05-30 14:39:56 <MrMobius    > so potentially very simple if a microcontroller is acceptable and youre not using an 8080 or something
2026-05-30 14:42:25 <Stalevar    > I like 8080 because it has very simple instruction commands, which makes it relatively easy to convert assembly code on paper or even think in machine code directly
2026-05-30 14:42:57 <Stalevar    > MrMobius, for example I wrote this thing to summarize 8080 ISA a while ago https://paste.rs/JyxAL
2026-05-30 14:43:35 <MrMobius    > Stalevar: I could see that. some others are good for that too
2026-05-30 14:43:38 <Stalevar    > You can't print 8086 complete machine code rules on single sheet of paper
2026-05-30 14:44:29 <MrMobius    > msp430 encoding is pretty sane
2026-05-30 14:44:46 <Stalevar    > Why not ez80?
2026-05-30 14:45:07 <MrMobius    > sure. if that's what you like. not sure if they have a microcontroller version
2026-05-30 14:45:39 <MrMobius    > up to you if you want to jump straight into building microprocessor circuits. it's way easier to start with microcontrollers and build up to it
2026-05-30 14:47:24 <Stalevar    > Another idea would be to make a front panel like IMSAI with switches and blinkenlights except maybe add a switch to decrement the address (you can scroll RAM only forward with examine next on Altair and IMSAI)
2026-05-30 14:48:07 <Stalevar    > But using more modern components to reduce number of chips
2026-05-30 14:48:31 <Stalevar    > and throw away s100 bus and such since  it's not meant as real computer
2026-05-30 14:50:37 <MrMobius    > you could do that with a microcontroller. would you consider another one like AVR, PIC, or MSP430?
2026-05-30 14:50:57 <MrMobius    > you could also run an 8080 emulator on a more powerful chip
2026-05-30 14:53:30 <Stalevar    > MrMobius, but I have got a real Z80 chip, it's like $2
2026-05-30 14:53:38 <Stalevar    > and 32k static ram too
2026-05-30 14:54:07 <Stalevar    > Z80 can be used as drop-in replacement for 8080, if you ignore extended instructions
2026-05-30 14:54:29 <Stalevar    > But doesn't need multiple power levels
2026-05-30 14:56:50 <MrMobius    > im not saying you cant do it. it's just a big project if youve never done it. that's why starting with a microcontroller is appealing and that could be $1-2 too
2026-05-30 14:57:08 <MrMobius    > you could also use a microcontroller to drive the Z80. that solves a lot of problems
2026-05-30 15:05:31 <Stalevar    > There are also STC89c52 learning board which already include 4x4 keypad and 7-segment display
2026-05-30 15:09:38 <KipIngram   > MrMobius - you could lead the "Federal Microcontroller Advocacy Agency," if there was one.  ;-)
2026-05-30 15:51:19 <Stalevar    > MrMobius, there are too many microcontrollers to chose from. Though I already have an STM board, an Arduino and Tenstar rp2350 USB
2026-05-30 15:52:05 <Stalevar    > For the latter there is already pico calc, where you can probably replace basic with assembly
2026-05-30 15:53:04 <Stalevar    > tabemann, by the way, can you install assembler editor instead of basic/micropython/forth?
2026-05-30 17:28:46 <xentrac     > MrMobius: according to https://en.wikipedia.org/wiki/Transistor_count#Microprocessors the original 8051 was 50000 transistors, which seems excessive
2026-05-30 17:30:54 <xentrac     > MrMobius: I'm still stunned that you found this 132×32 LCD for 70¢: https://www.buydisplay.com/cog-serial-spi-132x32-graphic-lcd-display-no-backlight-st7567a
2026-05-30 20:42:26 <tabemann    > back
2026-05-30 20:43:23 <tabemann    > Stalevar, I've never seen someone provide an environment for the picocalc that is literally just an assembler and an editor
2026-05-30 20:46:54 <tabemann    > Stalevar, about machine code-programmable calculators, I remember that back when I was in high school kids were loading programs written in machine language on their Z80-based TI graphing calculators
2026-05-30 20:47:55 <tabemann    > oh, btw, you can program under zeptoforth in assembly, even though the built-in assembler is limited to ARMv6-M assembly for the sake of compatibility across platforms
2026-05-30 20:48:32 <tabemann    > also note that the zeptoforth assembler uses its own Forth-based syntax rather than the standardish syntax provided by SEE
2026-05-30 22:07:03 <xentrac     > people also programmed the HP 48G and 48GX in machine language: https://www.hpcalc.org/details/1726
2026-05-30 22:08:45 <xentrac     > as well as the HP 41C: https://literature.hpcalc.org/community/hp41-mcode-beginners.pdf
2026-05-30 22:10:26 <xentrac     > the TI calculators have a third-party OS, KnightOS: https://www.ticalc.org/archives/files/fileinfo/463/46387.html
2026-05-30 23:11:22 <visitor     > .s for viewing the data stack is very useful - is there an equivalent word for viewing the return stack?