Going to Wisco

I'm heading to Wisconsin for the rest of the month. Not sure what I'm going to take with me or what I'll be able to get done if anything while I'm there. Over the last few days I've been heading in two directions...

One is newton programming. I've got the eMate out. UNNA has a great collection of Newton development tools, documentation and source code that is compiled onto a single HFS image. The NIE (Internet Enabler) pdf from Apple looks promising -- I'd like to write an mpd client for the newton -- but I think I might have to take it to a printer to get a hard-copy. It's too hard for me to digest large PDFs on a computer. Speaking of the Newton docs, I needed to find a pdf reader for OS9 and found Pure Mac, which has lots of versions of lots of things well organized.

The other thing I've been doing is playing many of the ascii games available on SDF, and in general exploring parts of the system I've ignored or overlooked in the past.

robotfindskitten 1.0.1

It might seem odd that you could write this game without implementing the arrow keys. Well I did, and it is. 1.0.1 now supports arrow keys!

rfk-mac68k-1.0.1.hqx
rfk-mac68k-1.0.1.img

robotfindskitten 1.0

Whew...

robotfindskitten-mac68k-1.0.hqx

robotfindskitten-mac68k-1.0.img

The disk image is a bootable 6.0.8 floppy suitable for vMac or BasilliskII.

Mostly I'm happy with it. The source code is included, but you can see the meat of it here if you just want to take a quick look.

There are a few issues. If anyone cares, I can fix them. No one will.

It's pretty fun. The 68k Macs can stand tall once again.

Robotfindskitten Update

Done

1. Movement
2. NKI Placement
3. Random Characters
4. Collision Detection
5. Kitten Detection

To Do

1. Import messages.
2. Display messages.
   
3. Win screen.
   
4. Introduction screen.
5. Color detection / colorize characters.
   
6. Macintosh niceties: icon, 'about', anything else?
   
7. Whatever else I'm forgetting.

Robotfindskitten Detour

It's not done, but I'm very excited about the progress I've made on my newest classic mac development project.

I first found robotfindskitten on my ipod Rockbox install. The game is almost too good to be true. Since then I've discovered that rfk has been ported to many systems, but not the classic Mac. Look at all those retro-systems represented and no 68k Mac.

Obviously all other projects go on hold.

What's interesting about this project to me is, the Macintosh doesn't lend itself to character-based programming as easily as DOS, C64, AppleII (etc) systems do, so I'm having to do a fair amount of extra work to get an ascii game working nicely.

What I've got done... so far I have a good engine (fingers crossed) for dynamically creating a grid based on screen resolution and character widths. A full screen window; leaving the menu bar.

TO DO:

1. Random placement of non-kitten items.
2. Robot movement and collision detection.
3. Import messages.
4. Win screen.
   
5. Introduction screen.
6. Macintosh niceties: icon, 'about', anything else?
   
7. Whatever else I'm forgetting.

MacTCP Programming

I spent several days fighting with MacTCP. I'm working on a full screen app that uses google weather to display current conditions and future conditions. Ultimately I'd like to create an internet "reader" that uses different XML APIs to gather and display info on the compact mac. I don't know how into it I am, but the Google weather will happen. Anyway, I spent many hours banging my head against the wall as I was fighting a not-always-reproducible-bug that was caused by a buffer overflow, incorrect LAN setup and prickly HTTP headers.

That's all sorted out, but I was hopping to at this point to have some simple XML parsing taken care of.

Also, I can't seem to take a screen shot of the full screen app when it's running. I'd like to show what I have. It's not very macintosh application "looking", and I've decided that style is just as important as function, so I'm not sure anyone else is going to ever want to use it. I guess you could say I'm giving into all of my design impulses which doesn't help any one else.

ZX Spectrum Assembly Programming Under Linux

There's been some Z80 activity on the BBS which sent me down - what I figured would be - a simple path... Write "Hello World" in Z80 assembler, assemble it and run it on an emulator.

The first place to start is the emulator. I installed spectemu (xspect) since it was available through debian's apt-get. It worked from the start; I didn't have to hunt down roms like other emulated platorms (68k, C64). If you're following along, at this point you should go download some existing Spectrum games and test everything out, make sure it works.

Next I installed z80asm and downloaded a simple assembly language program. Assembled it, loaded it into xspect and watched nothing happen. The output of z80asm is binary z80 machine code. The output of z80asm needs a piece of code added to the beginning of your binary file to get the Spectrum to load it. It also needs to be in a .tap file format. This code can be machine code, or basic. You don't have to understand, you just have to know it's required.

What to do? I was directed towards BIN2TAP and BIN2CODE on the SevenuP website. They have an .exe version for windows/dos, but also the c source code, which compiled fine with gcc. I have the files including compiled executables for linux x86 on my website here.

Many of the simple asm files I found for spectrum wouldn't assemble, or when if they did didn't work when run. I then thought to check the 99 bottles of beer website, and downloaded the Spectrum Z80 assembly version. It assembled without errors, and ran flawlessly. The 99 Bottles website is a great place to find a simple (but not too simple) program in almost any computer language you can think of, and it's often helpful when one needs a reminder after a few years away from a language.

Here's a link to the .tap and the .asm files of my Hello World app. Let it underwhelm you...

; Hello World in Z80 assembly language.
;  Assembles for ZX Spectrum
;
; Assembled/Tested under linux with the following tools...
; z80asm $@.asm ; utils/bin2tap a.bin $@.tap ; xspect $@.tap
;
; Author: Nathanial Hendler ; retards.org
; Adapted from Damien Guard's 99 Bottles of Beer on the wall...
; Adapted from the Alan deLespinasse's Intel 8086 version

org 32768

start:
ld      a, 2                  ; channel 2 = "S" for screen
call    $1601                 ; Select print channel using ROM

ld hl,line                    ; Print line
call printline
ret                        

printline:                     ; Routine to print out a line
ld a,(hl)                     ; Get character to print
cp '$'                        ; See if it '$' terminator
jp z,printend                 ; We're done if it is
rst 16                        ; Spectrum: Print the character in 'A'
inc hl                        ; Move onto the next character
jp printline                  ; Loop round

printend:
ret

; Data
line:    defb 'Hello, world.',13,'$'

Here's the bash script I use to assemble, convert to tape, and run the program; in case anyone cares (no error checking because I never make mistakes)...

#!/bin/sh -e
# Usage: ./makez80 hello

z80asm $@.asm ; utils/bin2tap a.bin $@.tap ; xspect $@.tap

Lastly, I found zxbasic on http://www.boriel.com/. It's a set of python scripts, and it includes one that assembles and outputs .tap files. It seems like an interesting suite of tools, and the fact that they're written in python makes them appealing for their hackability.

68k Greets App

The Overview

Well, it took several days longer that I expected, but I've finished my RetroChallenge "Greets" app. I've tested it on System 6 & 9. All the app does is display a list of participants and let you see the equipment they reported they would use in the challenge.

RetroChallenge-2008.hqx

The Hiccup

The worst thing is when one's code builds and runs fine within the development environment, but when you compile the application and run it on it's own: shit hits the fan.

I know what kinds of things cause this behavior, but that doesn't mean it's easy to track down. In this case it was an un-initialized Cell type passed to LGetSelect(). I just don't understand why it worked in the first place within Think Pascal.

TextToSTR#

This was an interesting find (found at Merlin's Cavern)... It's an application that takes a tab delimited file and creates a STR# of each row of data for each row in the text file. I thought this would be very useful, but it was only moderately useful as it truncates the data even shorter than the limits of an STR# string.

On the upside, it comes with Think Pascal and CodeWarrior sources so one can modify it for their needs. Anyway, I can see it being very useful, and I post it here with a thumbs up...

texttostr.hqx [2]

Thoughts

What I have now is the basic structure of a simply useful user-interface. This model, a list and window, can fit many needs for simple applications. While by no means revolutionary, it does scream very "Macintosh".

With a grasp of LDEFs, I think I'll revisit my MPD client and add playlist functionality.

Let me know if you run it. Especially if you have any problems or catch a bug. Thanks.

Very Active, Nothing Accomplished

How to make this interesting to anybody? Here goes...

The Mac Plus mod is on hiatus. I didn't kill the Plus, but it now has a switch hanging out the back that when activated gives it a bad attitude. Fun.

Some of the things I've been poking around with: LDEFs, Think Pascal, TransSkel, Vice (commodore 64 emu), Basilisk II, MPW.

All of the Z80 chatter on the BBS prodded me to install a Sinclair Spectrum emulator. I went with spectemu, downloaded all of the Spectrum games from the 2007 MiniGame Compo which I found through the Retrobits Podcast. I was a bit confused on how to load the games, so for anyone looking: Press "J" to get LOAD, then type to double quotes, hit return, start tape...

LOAD ""
{press play}

"Amazing" is a 1k game that I found particularly impressive.

I pieced together a nice LCIII out of two LCIIIs that I collected 5 or 6 months ago. The ethernet didn't seem to work, but that's because it has a jumper that was set to BNC instead of the 10BaseT jack. I'm not used to pre-auto-sensing hardware anymore, so that stumped me. Also the fact that one of the cards *was* bad, and then I got confused as to which one was which.

So now I'm still trudging forward, trying to get something produced I can show off. Several of the other RetroChallenge participants have really impressed me, and it's motivated me to find some focus soon. Of course, I don't really mind meandering through the land of retro-computing either.

Mac Plus Goes Under the Iron

In order to leave no suspense, let me say that so far it's not working. You can follow the story here.

Photos here:
http://www.retards.org/projects/retrochallenge/2008/Gallery/index.html

Hopefully Mr. Lee will have an idea, but for now I think I'll spend the next few days in the secure comfort of pascal as I'm in over my head with analog circuits.

Stock Mac Plus Temperature and Power Readings

Before I modify my Mac Plus, I wanted to get some baseline readings from the machine so that I would have something to compare the modified Mac against. Here are the results.

Power

This was pretty easy. A watt meter showed an average of 31 Watts (.44 amps) spiking up to 34W and .46 amps when accessing the floppy drive.

Over 2 hours (non-idle, but no disk access) the power stayed at 31 Watts until the very last reading at which it rose to 32 Watts.

Turning down the screen brightness had very little impact. At full brightness my Plus used .44 amps, and at full darkness it used .42 amps.

Temperature Test

4 digital thermometers were used to monitor the Mac Plus. None were inside the mac. None were the same brand. An indoor thermometer sat near the Mac Plus, monitoring the ambient temperature of the room. The second thermometer sat on top of the mac, but it doesn't have a probe, just holes on the top meant to read indoor room temperature. I used this one to also get an idea of the temperature around the Mac. Third was a digital cooking thermometer with the probe laid across the vents on top of the Plus. Last, another cooking probe was inserted under the Mac (between case and desk).

Is this the best setup I could have used? Obviously better sensors could have been used... A thermometer inside the Mac would give a more accurate reading... But that's not all... Air-conditioning was starting and stopping during the test, and an oscillating fan was running.

I decided to go forward with the used method for a few reasons. One, and most important, it's what I could do, but in addition, I wanted to measure the success of the modification, and to me that meant results good enough to be detectable in a real world environment. If the modification's results aren't detectable with the used method, then it's not a successful modification in my mind.

Temperature Results

Included with this post is a graph of the temperature results. The graph was created with Cricket Graph (1987) on a Mac SE running System 6.0.5. The PICT image was converted to a PNG using Graphic Converter 3.8.1 on an iMac using System 9.

The results show a 13 - 20 degree (F) increase in temperature over 2 hours. The Mac Plus was running a simple screen-saver during the test.

Thoughts

With the baseline tests done, I can move forward with the modification. I would really like to see significant results in power usage and temperature. Fingers crossed.

I might see if I can get the next graph published without using the iMac, Graphic Converter 3.8.1, or System 9; all of which are newer than 10 years old. Maybe I will, maybe I won't.

2008 RetroChallenge Preamble

• Project 1 (hardware): Modify a Mac Plus so that it is better suited for 24/7 operation. The idea is to generate less heat/power and prevent burn in by turning off the video circuit. I'll be using an approach suggested by Tom Lee on the 68kmla forum.
• Project 2 (software): Create another RetroChallenge participant list app that uses an LDEF so that I can learn how they work.
• Project 3 (software): We'll see.