doing that costing now:

it seems 6502s are about AUD$5.00 from china:

https://www.aliexpress.com/item/1005007495230134.html

https://www.aliexpress.com/item/1005009035226875.html

i have every reason to believe that they will arrive operational.

if we follow this construction:

https://github.com/adumont/hb6502

we will require:

SRAM (UM61256) ~ AUD$1.00
EEPROM (AT28C256) ~ AUD$10.00

also needed:

6551 ACIA ~ $5
6522 VIA ~ $5 (which we can possibly do without)

so the rough back-of-the-envelope price, just for ICs, is:

~ AUD$30.

about the same. hmm.

the idea behind all this fossicking is to try and build a little cottage industry hobby here for myself, manufacturing what i will call "the people's permacomputer".

if i am able to get these ATmega1284s working, it will be based around that IC.

if it turns out that some other method for running Tiny BASIC is cheaper and simpler than that, ie NOS Z80s or 6502s, etc, i will abandon the ATmega1284 and go with that other method.

#basic #retrocomputing #permacomputing

big news.

i found a spare loose ATmega16-16PU.

i was able to successfully flash a bootloader to THAT.

so BOTH the '1284 and '328 are dead.

i went and spent AUD$30 on another ATmega1284PU, in the hopes that this new one will not be dead.

photos coming soon.

been battling the arduinos all night.

i cannot get either of my ATmega328P-PU or ATmega1284P-PU loose chips to 'wake up'

i am, however, able to flash bootloaders successfully backwards and forwards between my arduino pro micro and arduino mega prefabricated boards.

so the problem is not with the programming side.

been running a matrix room about BASIC for some time now, and we do have some regulars from across that kind of federated chat:

#basic:solarpunk.au

do you have a matrix protocol account?

are you interested in retro technology?

if you click on this link, if will open up in your matrix client app and will allow you to join the room:

https://matrix.to/#/#basic:solarpunk.au

#retrocomputing #basic #matrix #matrixprotocol

ferrari designers drive citroens

think about that

the prime minister of my country name-dropped my activist party in parliament.

i am so happy.

all press is good press!

https://socialist-alliance.org/

#activism #funny #auspol #socialism #australia #communism #marxism

The code I have been following is a mixture of 8080 assembly, and 8080 assembly transposed onto Arduino assembly with macros.

And for the largest part of the code, it works. Given the ATmega chips allow so many addressing modes for the 32 general purpose registers a chip has, you can just define r24 to be an 8080 accumulator and have it work.

Macros are really useful in assembly language. Don't every forget to leverage the C preprocessor for Arduino assembly. Highly suggest at least looking.

Thinking about scrapping this latest attempt at a BASIC interpreter, and sitting down and having a think about what a nice BASIC would require for my purposes.

Array variables. Some nice string operations, such as INSTR() and LEFT$ etc.

I am getting stuck on following crabbed code from the 1970s. I have 8K of SRAM, a large complement of registers, and enormous amount of flash memory--256KB. The Arduino mega is quite beefy.

https://www.gammon.com.au/forum/threads/11635.html?id=11635

https://www.gammon.com.au/forum/threads/11637.html?id=11637

it seems some good capacitors are necessary on the breadboard.

i ordered five bucks of stuff from aliexpress:

10 x 20pF ceramic capacitors, for the 16 MHz crystal that MUST be connected by default in order to get the chip to wake up.

10 x 100 nF ceramic capacitors, for power decoupling.

1 x TinyUSB ISP programmer. if all else fails, i will use this.

please see the image attached for the recommended setup to install a bootloader:

battling the ATmega1284 again

would be fun to do a "BASIC running on things" series of photos

Dandelion BASIC is based very closely on the Dr Dobbs Journal version from the 1970s.

That version of Tiny BASIC was called Tiny BASIC Extended, authored by a man named Dick Whipple, and targeted the 8080 series of processors.

Whipple has his own website, and from that I gleaned that one may treat the Arduino as if it was an 8080, making the process of writing a BASIC from scratch much better guided.

Contains FOR/NEXT, two dimensional arrays, but sadly not many string operations.

Been slowly warming up to the process of development for Dandelion BASIC.

There are some powerful tools that one can have at their disposal on Linux.

The GNU debugger, gdb, has support for the ATmega series of chips. You can set breakpoints and inspect register contents.

My makefile works, and I am able to successfully assemble files. Much of the learning curve so far was getting to assemble anything at all.

I recommend using the C preprocessor to make your life easier with macros.

https://codeberg.org/vidak/dandelion

Thinking about Dandelion BASIC, the Tiny BASIC that I am writing in assembly language for the Arduino Mega.

The method I am using is the "interpretive language" one. A type of virtual machine is set up which is what actually runs BASIC. Everything written in assembly language for the Arduino is just routines for running that virtual machine program.

The difficulty curve is steeper, but the long tern benefit of the method is that you can modify and extend the BASIC far easier.

#retrocomputing

@screwlisp beep i am available at the usual time, if you have capacity to record the show?

The second anniversary of this post is coming up, and surprise surprise these little "end of life" laptops are continuing to run well with #linux and do what we need them to, which includes spending less on tech so we can buy more actual books for the school library. #schooltech #endof10 #edtech #foss #reading #kidlit

Still getting my arse kicked at Zelda Breath of the Wild ha ha

https://www.greenleft.org.au/2026/1464/world/france-workers-mobilise-support-inspiring-school-student-revolt

#france #protests