trying to max out my LC2

[Osgeld]

This has been an ongoing process, but here is the rundown

I got a mac performa 430 (aka LC2) from a thrift store for 99 cents about 4 years ago, at the time all my 68K mac needs were handled by my basic SE and I have not owned a color 68k mac since my IIcx back in the 90's

the performa sat mostly unused until I recently got my apple IIe card, my retro computer desk is mostly populated with 2 redudant mac's (the SE and the LC2) an apple IIC, a Pentium and either an Atari 65XE or a C64. Needing to thin the herd a bit I thought it would be cool to max out the LC2 replacing the SE and getting an apple IIe card to replace apple IIe functions

the LC2 is a dog of a machine, rom limited to 10 megs max memory, 32 bit cpu on a 16 bit buss and a slow 16mhz cpu, but for 99 cents... lol. I did scavenge an additional 8 megs of ram for it bringing it up to 12 megs (though it only addresses 10 thanks to the wonky rom and 4 megs on board) and a video ram upgrade which allows for 640x480x256 colors.

First order of biz was to wire up a mac to VGA cable which works perfectly with my year 2000 era 20 inch Mitsubishi monitor, this may not sound like a big deal but almost every LCD made will either not display any picture, or present a bitch message in the center of the screen about the not quite perfect vga mode of the mac ... I tried a half dozen LCD screens over many years before my Mitsubishi was retired from my main gaming machine display hehe.

Next thing was a motherboard recap, the machine was fairly unstable under stress and there was a lot of noise form the speaker, little hot air and a raid of the new cap stash quickly solved that.

Of course shortly after the stock 120 meg hard drive started to exhibit stiction on the heads, and the only way I could get it to boot was to remove the cover from the hard disk and physically move the heads from park position every single time on startup. Small size SCSI hard drives are not the most common thing in the world and for a minor price more I got a apple branded 1gb quantum, which is of course totally overkill for a 16mhz 68k machine, but the price lined up with what I was willing to fiddle with so there it is.

so flash forward to October 2015, we have a newborn, its hard to get away let alone isolate myself to the dungeon basement, and im starting to itch for classic mac and my apple IIc, which was at least a once a week all day event. I had been searching for an apple IIe card for quite a while but most ebay prices offended me. I finally came across one for a reasonable price with the elusive Y cable and I snagged it.

Once I bought it I started looking around and seeing the dismal performance of the card, and thinking OMG what have I done, this thing is crap! and frankly it is .. with OS 7.55, it runs terrible!

so to boost performance I added a FPU, the stock solution to this is to add a card, but with one slot I wanted that to house the apple II card. Right next to the CPU is a 68 pin unpopulated spot, sucking out all the solder from that spot I then added a 68 pin plcc to though hole socket.


from there I added a 68882 FPU and gee wilikers it works! After that I removed the stock 31.xxx oscillator and replaced it with a dip 14 socket with mos of the pins removed. At first I bumped it up to 40 mhz which gave me a 20 mhz cpu over the stock 16. Works like a champ, pushing it forward I added on a heatsink and a 50Mhz oscillator giving me 25 mhz, the cpu and serial ports work perfectly but the sound is garbled, so I think I need to drop it down to 48Mhz to restore sound given math n junk.


even with a 4Mhz bump to 20Mhz total the system is much more responsive and games, even though they still run at laughable FPS actually respond to input in near real time. Next thing I did was drop the system OS from 7.5.5 to 7.0.1 and and what do you know the apple IIe card went from less than half speed to just about indistinguishable from the real deal machine

so as of right now

0.99$ mac
1.99$ adb keytronix keyboard with trackball from thrift store
30$ apple branded 1 gig SCSI hard drive - used from ebay
25$ griffen Imate ADB to USB adapter so I can use the same keyboard with the pc on the same bench
15$ worth of 30 pin simm memory
1.59$ PLCC 68 Socket
9.99$ 68882 PLCC FPU
89.99$ Apple IIe card
16.00$ worth of radio shack crap to make a ADB switchbox and a null modem adapter to communicate to the PC
30.00 for a apple II 5.25 inch drive

or another words 220$ on a craptastic mac that replaces the functions of 2 machines I already have ...before postage... and hours worth of piddle farting around...

GOD YOU GOTTA LOVE RETRO COMPUTERS LOL

 

[kyodai]

Well well, for 99cent it was sure a bargain - for 220 bucks... You gotta love System 7... The Apple IIe card is of course pretty cool. Here in germany i saw one in stores as late as 1995 and back then i thought like "Lol, who still cares about that?" It kinda was already retro the day it was released, so pretty much the coolest add-on card ever released. Personally i like MacOS 8.1 - kinda farewell from the 68k gen, so imho you also need a maxed out 68k based 8.1 system Oh and Microsoft Internet Explorer 3... Oh well these were the days... XD

 

[GiGaBiTe]

Oh man, I remember using LC and LCIIs in elementary school, they were so painful. When the school started replacing them with power macintoshes, kids used to fight over those because they dreaded being stuck on such a slow machine.

The school techs tried to squeeze every last drop of life out of them by maxing out the RAM and installing both speed doubler and ram doubler.

I have an LC III myself which I "chipped" from 25 to 33 MHz, it gives it a pretty decent speed boost.

 

[olePigeon]

For your LC's video problems, you'll want to get something like this:

http://www.ebay.com/itm/HD15-VGA-Mo...ter-Adapter-with-6-DIP-switches-/222026064458

A passthrough cable may not work, so you want one that'd adjustable. This will allow you to change the sync and refresh settings on the adapter so that you're certain you're getting the correct signal to the monitor. The sync options are perhaps the most important.


Also, since it is an LC II, it needs to be recapped. All Macs of that era need to be recapped.

 

[GiGaBiTe]

Those adapters with dip switches and rotary dials don't do any signal conversion. The purpose of those settings is to fake out the Mac its attached to so the Mac thinks it has a certain type of display attached.

I've rarely had luck with those on 68k Macs because they have weird refresh rates like 67 Hz. The screen resolution setting sometimes works if the Mac has support for that resolution.

 

[Osgeld]

aye all the switches do is change the configuration of the sense lines, I just have my homemade adapter hardwired to 640x480 (the max this machine will do), on super old color mac's you have a choise of apple monitors, which are all weird, and VGA (sometimes SVGA) or if you want to get really weird they will put out monochrome ntsc / pal (color too if you gizmo up a rgb to ntsc converter, but why?)

the problem with mac 640x480 is the timings, like line length, on pc vga its 31.78uS on mac its 28.57, sync pulses are slightly longer etc, this doesnt really matter on most CRT monitors as they are mostly dumb analog beasts. With LCD screens however they require analog to digital conversion with some level of smarts in them, so oddball timing either results in a blank screen or in the case of a IBM monitor i tried a perfect image, blocked by a OSD of "unsupported resolution"

This all of course is corrected in later model macintoshes, and by power pc era a forgotten annoyance

ps: I recapped it like last year

 

[olePigeon]

Oh, OK. Well, with my LC and even my IIci, I can't use a pass-through adapter or even official Apple monitor cable. None of my LCDs will detect it. I have to go through an adapter with dip-switches. I usually set it to multi-resolution with Sync on Green, and that (so far) has worked with any LCD I've thrown at it. Maybe it's the Sync that makes all the difference for me, I don't know.

 

[Osgeld]

might be never thought to use sync on green