Turning the Apple //e into a lisp machine, part 1

http://blog.nullspace.io/apple-2-lisp-part-1.html

by antics • 13 years ago

169 62 13 years ago

blog.nullspace.io

antitrust4• 13 years ago

The Apple //e was the hacker-friendliest machine ever. It's probably the ideal learning platform for anyone looking to go into computer science, although perhaps not app programming as a career, which requires a narrower skill set and more focus.

zwieback3• 13 years ago

I was a die-hard Apple fan until the Mac came out, which felt like a betrayal to the original Wozniak-driven Apple philosophy. The PC, ironically, became the continuation of what Apple meant to me.

analog313• 13 years ago

I suspect that their experience with the //e influenced the decision to make the Mac a closed box. Like you, I found the PC to be a much more comfortable transition.

Because the Apple ][ was a locked design, folks started poking directly into ROM and RAM locations, for instance directly manipulating system variables, or even jumping into the middle of ROM subroutines. A book called "What's Where in the Apple II" documented almost every known hook.

My mom had that book. She's my hacker role model.

As a result of the way that software interacted, it became virtually impossible for Apple to update the ROMs without breaking popular apps.

The next generation of personal computers all represented different approaches to avoiding this problem by providing well documented entry points while offering no guarantee of long term code stability. IBM made one mistake: They let people hard code the address of video RAM, which is what led to the legendary 640k barrier.

antitrust4• 13 years ago

This was my experience exactly. I loved the open Apple //, even though it had limited growth potential. I found the Macintosh to be confining (and still do, although more in an interface design sense now).

rumbler3• 13 years ago

Same here. I went from an Apple IIe to a Macintosh SE. It was a nice computer for typing high school papers on (yay PageMaker 1.0), and the GUI of System 5 was beautiful on the little black-and-white screen. There was some hacking involving fonts, inits, and ResEdit, but despite despite getting a C compiler and a few books, I never was comfortable programming on it, and always felt like there was something missing.

Two years later I got a '386 clone, bought Turbo C and all the fun came back at once.

Vivtek• 13 years ago

It certainly worked for me.

jff2• 13 years ago

A Lisp machine is designed at the hardware level for running Lisp well. This is a neat project to implement a bare-metal Lisp environment on top of Apple //e hardware.

antics7• 13 years ago

This is true, of course, but our point is that there is not a lot of stuff separating the lisp from the machine -- no OS for instance. It's just a machine that runs lisp and nothing else.

lispm3• 13 years ago

I think its fine and a good project. I was once using Lisp on my Apple IIc.

Generally a Lisp Machine is also really a piece of hardware designed to run Lisp. The CPU of a Symbolics for example is a (mostly) stack machine which knows all kinds of Lisp data types and Lisp function calling conventions. The memory then also contains Lisp data (with tags for data types and GC which are used by the CPU directly). Additionally the Lisp that runs on top of it is providing OS services: device control, I/O, keyboard, disks, tapes, expansion cards, graphics, sound, network, scheduling, ...

Getting a Lisp on an Apple II to the level of the built-in Apple Basic with access to keyboard, graphics, etc. should be fun. I'm looking forward to read more of your adventures!

jff2• 13 years ago

It's damn cool in any case, looking forward to future articles!

hcarvalhoalves• 13 years ago

Which makes you wonder, where would we be today if the Apple //e shipped with LISP.

harrytuttle• 13 years ago

Probably not have shifted bracket keys :D

sehugg2• 13 years ago

In those days I'd just be happy with a language that let me quickly manipulate 16-bit integers. AppleSoft used floating-point for all intermediate calculations, which made even simple loops very slow.

I enjoyed using GraFORTH, which was a 10 kb dialect of FORTH with bitmapped and 3D wireframe graphics (!) that compiled to threaded code.

rumbler3• 13 years ago

Steve Wozniak's original Apple II Integer Basic had 16-bit signed integers, but no built-in floating point support.

Applesoft (licensed from Micosoft) had 16-bit integer variables (such as A%) as well as floating point, but you are right that it converted them to and from real with every operation, which was slow. They were useful for saving memory (2 bytes instead of 5) and not much else.

There were BASIC extensions published in places like Nibble and Call-A.P.P.L.E. that added native integer math to Applesoft using the & command, so you could write things like "A% = B% &+ C%", and the operation was performed without conversion to real.

Let's also not forget SWEET-16, Woz's software emulation of a 16-bit kind-of-RISC processor on the 6502, that had 16-bit arithmetic. Reading the source code of SWEET-16 blew my young, impressionable mind.

sehugg2• 13 years ago

I wonder if Andrew Plotkin's "Lists and Lists" (a Scheme tutorial written for the Z-machine VM) can run on a //e? Seems like it would.

http://ifdb.tads.org/viewgame?id=zj3ie12ewi1mrj1t

zwieback3• 13 years ago

Nice blast from the past. I eventually built a serial port for my Apple ][. I bet you could do a USB-FTDI-Apple interface pretty easily. The audio interface was always really fiddly although we used cassette tapes back then and most of the problems were due to the low fidelity of the tapes.

antics7• 13 years ago

Interestingly, in practice the laptop-to-A2e audio transmission almost never fails -- the fidelity is probably not an issue anymore. FWIW, we would have picked a better way to transmit the data if we'd had more hardware. This was basically just a hack that ended up being kind of funny and cool.

lscharen3• 13 years ago

He should really look into using ADTPro. It even supports bootstapping over the audio input like is described in the post.

http://adtpro.sourceforge.net/bootstrapaudio.html

antics7• 13 years ago

But then it wouldn't have been a hack! We wouldn't have had to understand anything to get the job done!

... Though, credit where credit is due, the C code we used to generate the audio signal actually is pretty much a direct port of the corresponding code in ADTPro. One of the reasons it's released separately from our lisp code is because ADTPro is LGPL and we prefer the MIT license. :) One of these days I'll make the port more independent and less derivative, so they can all be in the same project.

lscharen3• 13 years ago

Might I suggest adding something to your project description that acknowledges this. I didn't see any mention of ADTPro or David Schmidt on the linked page or the github repository.

David Schmidt has contributed a lot of free software to the Apple II community over the years and, IMHO, deserves recognition for his work by those that build upon it.

fsck--off• 13 years ago

If you want to play with a Lisp Machine on Apple hardware, Symbolics is still selling refurbished MacIvory boards. Even though the hardware is ancient the latest model (MacIvory model 3) costs more than a top-of-the-line retina MacBook Pro. The MacIvory 2 is more affordable, if you have an extra thousand dollars to spend.

http://www.lispmachine.net/symbolics.txt

lisper3• 13 years ago

Another Lisp for the Apple II:

http://www.flownet.com/ron/plisp.html

Complete with disk images so you can run it yourself on a real Apple or an emulator.

msarnoff• 13 years ago

The documentation link on that site isn't working, but it can be found here: http://jeffshrager.org/llisp/

The last chapter is particularly interesting, as it describes the inner workings of the interpreter.

lisper3• 13 years ago

Thanks! Fixed.

richardjordan• 13 years ago

I still have my original Apple II from when I was a kid. Have been meaning to fix it up in a while. This is a great reason to do so! In other news, any hardware hackers in Sunnyvale looking for a fun project...

antics7• 13 years ago

We (or I) actually read your writeup before approaching this, Ron! It did impact some of our design decisions. :)

lisper3• 13 years ago

Cool :-) BTW, I started working a while back on a Lisp to run on a Teensy 3:

http://www.pjrc.com/store/teensy3.html

Never finished it, but if you like these kinds of challenges maybe you'd like to collaborate on it.

LarryMade22• 13 years ago

There is no assembler and no text editor, so the only development possibility other than BASIC is to implement directly in machine code.

Could have developed off machine then ported over to the ][ lots of resources here: http://6502.org/

like XA65: http://www.floodgap.com/retrotech/xa/

Much 8 bit development nowadays (and there still is a lot) is cross-platform.

plus many many apple ][ emulators for debugging... even some running via browser.

billforsternz2• 13 years ago

Well yes, and that's exactly what they did; Developed off machine and then ported over to the ][

LarryMade22• 13 years ago

But.. there are assemblers/compilers... and available off-machine. Just pointing out an undiscovered opportunity.

cdjk• 13 years ago

This is very cool. For a slightly easier way of experimenting with a lisp machine it's possible to install OpenGenera. There are scattered tutorials online, but here's one I've found:

http://www.cliki.net/VLM_on_Linux

I've been meaning to try this - perhaps I'll write up a better tutorial (or better, an ansible playbook) to set it up.

hvs• 13 years ago

Aw crap. Now I may have to setup my Apple IIGSs and begin another marathon Apple hacking session. My wife always finds these times trying/amusing/annoying.

rbanffy3• 13 years ago

One of my personal projects (one that'll most likely never happen due to time constraints) is a Raspberry Pi-ish gizmo merged into an Apple Super Serial (or something with a built-in terminal). This way, you could plug it into a slot and boot into a terminal of a Linux machine.

tcarey83• 13 years ago

I'm gonna stick my neck out here and say these guys are choosing the worst and most convoluted way to develop software, much less, a lisp system to for the Apple IIe ever. And then, trying to make a sensation out of it.

I was alive and programming back when the Apple IIe was popular. While I mostly wrote code for the Commodore 64 and Atari systems of the time, I did write a bit of code for the Apple II and IIe.

Those computers are primitive by today's standards, but nobody was entering hex codes. That ended with computers like the ELF II. A lot of the machine code programming was done with a program called a 'monitor' program that was much like the DOS debug program that allowed viewing and writing memory as well as a single line assembly (i.e. inline assembly) that would allow writing programs a line a time in assembly.

But most of the programming was being done using assembler's and compiler's like the Aztec/Manx C compiler that is still availble today (google it) so what they are doing and saying is BS.

Turning the Apple //e into a lisp machine, part 1

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