https://www.youtube.com/watch?v=D_ta5QxBSMk&t=42s

I must have missed that one. That is spectacularly twisted, to do it by injecting a stream of code via an I/O window. Kudos to Chris Morley.

It won't help the OP, who is stuck with bit-banging, but I did something similar ages ago for my own ...

For me schematic is still the closest equivalent of AND-OR matrix going to a flipflop with feedback and expander--the heart of a macrocell. When I design in schematic I can best visualize how it is implemented in macrocells.
I always glanced at the actual RTL to get a feel for that (Tools ...

Schematic entry is not lower level design. Your primitives in schematic entry are just HDL coded modules, under the hood.
My reason for designing in schematic is because it is closer to the actual logic implementation (which you appears to disagree) that I can pack more functions with schematic ...

PS, lots of EPM7xxx on eBay are JTAG-locked, but I took advantage of eBay return policy and keep buy-and-return until I found vendors with unlocked EPM7xxx.
In addition, a lot of EPM 'S' on Ebay are not actually 'S'. I once bought a batch of 200 EPM7032STC44 on Ebay, which (eventually) turned out ...

In Quartus you can enter designs as schematics of logic gates, flip flops, even TTL library components. It is graphical design entry instead of HDL text. It is a lower level design where each macrocell is accounted for.
Schematic entry is not lower level design. Your primitives in schematic entry ...

Just in case one had the time and energy and motivation, there's Acorn's BAS128 and John Kortink's 816 port of Acorn's Basic (4r32 plus fixes, I think) both of which arrange to make memory accesses into a separate 64k space. Unless perhaps John's allows for more than 64k.
It does. It basically ...

I photographed the front and back of the bare Atom PCB I had (mentioned earlier in the thread), before I built it up with parts. They are 4000 x 3000. If you want them, let me know.

A sidenote of possible use : I discovered some years ago, when I was busy with my own project, that SiI164 is a clone of TFP410 (and does not have and/or need the thermal pad). The SiI164 is a lot cheaper, but does not seem to be easily available (much like the TFP410 right now ...). Both are ...

A bit of an out-of-interest or forward looking post on my part but... has anyone generated an HDMI video signal from a frame-buffer?
I have used a TFP410 in this : https://www.zeridajh.org/hardware/bbc2dvi/index.html . Because, as you may know, HDMI is basically DVI (and TI likes to call it ...

In SPI mode, the assertion of CS marks a byte boundary. Also, the clock polarity is expected to be the same on assertion and deassertion of CS (a.k.a. 'mode 0' and 'mode 3'). So, in SPI mode at least, after (re)asserting CS, bit 7 is expected, always.

Even DJ of EEVblog reviewed a single channel version from KORAD and gave it a thumb's up, although given it was not a Keysight or R&S he had to hold his nose and wear gloves to do it. But in reality, most of us do not have $27,000 to spend on a bench PS (if you do, I don't want to hear about it (jk ...

Imagine that in 1975. So forward looking.

The nice thing about conventions is that there are so many to choose from (paraphrasing Tanenbaum).

I looked at your tiny core, but could not get my head around the memory access. How do you wire all those PEEKxxxx input/output instances into a single dual port?
Somehow, I must have missed your message ... Anyway :

You connect the 8xNs to their own memory blocks (they're just a page each). Only ...

I would expect the ','s to print, followed by the '!'s. Instead I get the ','s then garbage.
Any insight into what I'm doing wrong or misunderstanding about how all of this works would be greatly appreciated.

My first guess would be that something in _lcdPrint corrupts the stack (and therefore ...