Re: Needing help upgrading a IIe!

[dempson@atlantis.actrix.gen.nz (David Empson)]

In article <4qr7fj$mbh@usenet11.interramp.com>,
Tom Zuchowski  <cd003508@interramp.com> wrote:
> smtrimbl@kuhub.cc.ukans.edu (Shawn) wrote:
> >Hello all,
> >I'm considering upgrading an old IIe and have a few questions I was
> >wondering if anyone could help me out with.  I'd appreciate any input or
> >suggestions as to the upgrade!
> >
> >1)Are there any disadvantages to enhancing?  Any ][ programs incompatable
> >w. 65c02?
> 
> None that I know of

I know of one that was definitely incompatible: the original version of
Apple LOGO.  It used an illegal (undocumented) 6502 instruction as part
of its copy protection (cringe) scheme, and this was broken by the 65C02,
which implemented the opcode differently.

It was possible to fix this by deprotecting and patching the disk.

There are possibly other programs that have similar problems (the same
applies to the IIgs: there may be a small number of programs that are
using undocumented 6502 instructions, or relying on a 65C02 treating
unused opcodes as NOPs, and these instructions behave differently on
the 65802 or 65816).

> >3)Now, what about an accelearator like the Zip Chip?  What's the maximum
> >cache & MHz?  (I'm guessing from what I've read so far that it's either 4
> >or 8 MHz & 16k cache...)
> 
> As far as I know, the 8-bit ZipChip only comes in one size these days, the 
> 8mhz one.  I thought it had an 8K cache, but I might be wrong.

I also think it is 8K.  The IIc+ uses the internal components of the
ZIP as its accelerator, and its circuit diagram shows 8K TAG and 8K
DATA RAMs, thus 8K cache.

An important point about accelerators in the IIe: none of them are
compatible with DMA, so if you have an Apple High-Speed SCSI card,
RamFast SCSI card or other card that uses DMA, you must disable the
DMA features.  Not surprisingly, this slows down disk I/O quite a lot.

This is not a problem on the IIgs - the ZIP GS and TransWarp GS are
able to support DMA.

> ProDOS can recognize up to (I think) 8 32MB drive volumes.

In theory, it could recognise 14 volumes, but only if you are running
ProDOS-8 2.0 or later (requires an enhanced IIe) on a 64K machine (or a
RamFast with an earlier version of ProDOS).  On a 128K machine, S3D2 is
reserved for /RAM, so you are limited to 13 hard drive volumes.

The catch: to get this many volumes, you would not be able to have ANY
floppy drives installed.

Assuming your only other disk interface is a Disk ][ controller (or
UniDisk 5.25 controller), you will be able to get 11 partitions.  If
you have two disk controllers, you will be able to get 9 partitions.

(Note: the original Apple SCSI card is limited to 7 partitions.)

If you have an Apple SCSI card, the main difficulty is the actual step
of partitioning the drive.  The software supplied with the card is
hopeless.  (The High-Speed version lets you set up 4 partitions, the
original card one only two.)  There is no readily available
third-party software for the IIe to let you create more partitions.
Chinook SCSI Utilities is my favourite, and it lets you set up nine
partitions, but it isn't available any more.

One option is to get someone with a IIgs or a RamFast card to set up
the partitions for you.  The Advanced Disk Utility program on the IIgs
can create eight partitions, more if you have a hard drive larger than
256MB and you do things in the right order.

> Note that to access this many drives, your IIe MUST be enhanced and using 
> ProDOS 2.x. It is this version of ProDOS that has the ability to map extra 
> partitions into other slots; if I remember correctly, older versions just 
> don't see the extra partitions if there are more than two on the slot.

ProDOS-8 1.2 through 1.9 are able to access four partitions on a
SmartPort or SCSI card in slot 4, by remapping two of them into slot 2.

The RamFast SCSI card is also able to remap drives to any slot with
ProDOS 1.9 and earlier.  (This feature must be disabled with ProDOS-8
2.0 or later, or ProDOS must be patched to disable its own remapping,
or you get very bad things happening.)

> >6)Someone told be that It'd be more worth my while just to simply find a
> >][c+ somewhere... would there be any advantages to having a ][c+ (provided
> >I could find one, which I'm told is tough) over a somewhat souped-up ][e?
> 
> I don't see any advantage to the IIc+.  Add-ons like large RAM cards are 
> hard to locate and expensive, and the IIc+ isn't NEARLY as fast as an 8mhz 
> Zip!!!

It is about half as fast - it has a 4 MHz ZIP built into the
motherboard.  That still means it is considerably faster than an
unaccelerated Apple II.

-- 
David Empson
dempson@actrix.gen.nz
Snail mail: P.O. Box 27-103, Wellington, New Zealand