Monthly Archives: October 2020

Apple IIGS “PVT/Prototype”

opened_s

I obtained this interesting and rare prototype or “Preproduction Validation Testing” (aka: Vegas PVT) Apple IIGS lately. It didn’t come with prototype memory card “Vegas” or “Zeus – RAM CARD” marked Expansion Memory card. The power supply looked regular GS powers upply just without the apple sticker on top. Astec AA13591, Model 699-0127, 230V 50/60HZ with date 8627, Revision 01. 

 


What is : “Apple IIGS Vegas PVT” ?

PVT stands either “Prototype Version Test” or “Production Validation Testing” simply meaning revision ment for testing and product/software developemtn before actual production started.

Vegas was development name for Apple IIGS – but also various other codenames while the new system was being developed including: “Phoenix”, “Rambo”, “Gumby”, and “Cortland”.” 

Few different board types were used during the “Cortland” project :
1985 Cortland board was blue, no SKA321-03 marking close to memory chips on right side.
1986 Cortland board was green, with SKA321-03 marked close to memory chips on right side.

The case and serial number:

case_front_s

The case seems to be early, regular IIGS production model.

 

case_back_s

The back seems to be standard as well.

 

case_bottom_s

The bottom.

 

serial-gs-pvt-ireland_s

Model : A2S6000W  (Wonder what the “W” stands for?)
Serial number: C63800JA2F6000 (Wonder what the “F” stands for?)

If i figured this out correctly then it would mean :
C 6 38 00J A2F6000
CORK
1986
WEEK 38
J = 18
0018 (unit no)

 

serial-gs-ireland-rom01_s

Compared to regular Ireland made GS, serial : CK9120PLA2S6000 (Year 1989, Week 12, Unit 802, ROM01) does not have “sticker” but it’s pressed to plastic directly – serial number part itself, is a small sticker. The ones made in 1987 have the same type of layout as well.

The main logic board:

 board_s

SKA321-03 board layout.

board_left_bottom_s

Left corner:

 

ska321-03_s

Close up: the motherboard pcb is green with “SKA321-03” printed in yellow below the are where the FAST RAM chips are. 

 

gs_1987_s

Close up: while the normal production revision the same position reads “Apple //GS”. 

The VGC is soldered into the main board, not socketed – just like early ROM0 boards.

Date on board : P8615 (next to SKA321-03)
P8615 is : 15/1986 (week/year) 7-14. April 1986
Close to barcone : 351 (very faint)
Close to barconde : 8618 (left side)
Code on board : 6xx-xxxx-A (top right next to slot 7)

 

Chip dates and codes:

CPU : C65SC8160-4 / G8549 
RAM : 8531 (all)
Audio – Ensoniq ES5503 : 343-0051-A / 8701  
Sound GLU : 344S0052-1 / 8605
MEGA II : 344S-0047
VGC : 343S-0046-1 / 8611 
KBD GLU : 344-S-0048
FPI : 344S0050-1 / 8641
ROM code & version : 342-0077-B / 8727 (ROM01)

Codes for early ROM are:
341-0077-A = ROM BF (=addon extension-board with 4 x 27C256 EPROM)
342-0077-A = ROM 00 (September 1986 – August 1987)
342-0077-B = ROM 01 (September 1987 – July 1989)

I’ve reason to believe when this unit was produced it came with the ROM BF. The case was obiously swapped later on – as it most likely originally came in //e case.

 

Serial number decoder:
https://debug.ninja/tools/apple2_serial/

Apple IIGS serial numbers list : https://docs.google.com/spreadsheets/d/1UB9TyF1h3mDyUXQgGm3Z7gxENAGOTFwL1fwLySoBRyU/edit#gid=1

 

FinApple 2020 (c)
Apple II Forever.

 

 

Apple ][ mouse modification:

signed_by_2_s

Marko Laaksonen, 18/09/2020

This is Apple M0100 mouse modification from 1992. My friend Paul was studying at the Helsinki University of Technology during the early nineties.

The University had had Apple Macintoshes and replaced their equipment base with PC:s. Some members of the ICT helpdesk / -staff had tried saving some money and had tried using those older Apple mice with those completely different type of computers (As I would recall the matter from the stories of my friend from way back then.)

top_s

The aforementioned act had resulted with a bunch of broken / inoperational M0100’s (and possibly other) Apple mice.

bottom_s

Paul studied the insides of the M0100 and figured out the “SNx4LS14 Hex Schmitt-Trigger Inverter” had a certain function in the mouse. The IR-led/IR-detector pulse-form is not sharp enough (LED’s are known to have a “lag” / slowness within them.) The Schmitt-Trigger  SNx4LS14 provides a function called “hysteresis” which makes the waveform of the mouse output more “square-wave” -like. This can be observed also with an oscilloscope.

After figuring out the aforementioned, my friend decided omitting the Texas  SNx4LS14 completely and instead of that one using separate transistors suitable for that purpose.

The build/experiment was succesfull and he got those broken mice working again!

mouse_mechanism_s

As I now can see from the specs, no more than 200 milliamps should be drawn at +5 volts. I’ve used that kind of a modified mouse with the Apple//c pretty long periods of time and there has been no problems with it. I don’t remember if a ballast resistor / front resistor was / had to be used.

The aesthetics of the repair / build is not exactly “Steve Jobs -approved”  but it works all the same. Nowadays people would probably just replace the original IC. This is still pretty interesting study of a principle in practice.

Currently this mouse is not working. There’s atleast one wire that needs resoldering. 

Thanks to Marko for this artefact.

 

FinApple 2020 (c)
Apple II Forever.

 

vTech Laser 128E/EX/EX2 memory expansion card:

all_parts_for_the_kit_s

This is a clone of memory expansion card for Laser 128E, EX and EX/2 models, 702175 Rev.C – made by Renee Harke. It’s not compatible with the FIRST revision of 128 but is with the later, 128E. I have the -E revision (later motherboard design with the RAM-expansion port).

It provides up to 1MB of “Slinky” RAM for the Laser 128 aka you can use it as RAM-disk etc.

renee_harke_s

See more details a:
https://reneeharke.com/tech/2019/12/31/laser-128-memory-expansion.html?fbclid=IwAR0qxykFwOPGudYMXQEdqquYckDdlJE7JZo2yfnLaZVZBsJCILKgBvyK0HY

Renee sells this either as a kit with all parts included or fully soldered ready-to-be-installed.

I bought this as a kit with all parts included because soldering is fun!

installing_ram_s

After soldering (took few evenings as i didn’t have the time to put on this project in one-go) i used the quite handy tool sold in ebay (few euro’s) that bends the IC-legs (it has two different sizes) to correct angle – so they are easier to install to the sockets.

 

ram_installed_s

I had removed the metal shield already as it’s pain to install back .. so installing the card was pretty easy and straightforward. Renee even included the 3 little screws needed for installation – that’s nice detail and good thinking.

laser_128e_back_opened_s

Installing the case back together is slightly more frustating compared to //c – even it’s very similar design. I’m really not a fan of the plastics vTech used…

slot_5_intnernal_enable_s

Also need to configure the Slot 5 as “INTERNAL” for the RAM.

ram_test_s

The internal RAM test can be found from the monitor (CALL-151) and then typing C50AG  … i was happy my soldering was successfull…. it worked!

 

test_prodos_s

..and it was seen by the ProDOS as correct size.

ready_s

FinApple 2020 (c)
Apple II Forever.