Caple C871i Bedienungsanleitung PDF herunterladen (Seite 174)

Apple II Computer Info

#############################################################################

### FILE : genericio.specs

#############################################################################

### Created : Tuesday, November 17, 1998 Modified: Tuesday, November 17, 1998

### File Type: "TEXT" File Creator: "LMAN"

### File Size: 7359 bytes 7 KB

#############################################################################

From: "ntt" <[email protected]>

Newsgroups: comp.sys.apple2

References: <[email protected]> <Pine.SOL.3.96.981114110324.27535A-

100000@moose> <david.911171291@wraith>

Subject: Re: Hardware Project

Date: Tue, 17 Nov 1998 08:08:37 +1030

Lines: 76

X-Newsreader: Microsoft Outlook Express 4.72.3110.1

X-MimeOLE: Produced By Microsoft MimeOLE V4.72.3110.3

NNTP-Posting-Host: pppk56a-77.mtx.net.au

Message-ID: <[email protected]>

X-Trace: 17 Nov 1998 08:06:29 -1050, pppk56a-77.mtx.net.au

Path: news1.icaen!news.uiowa.edu!news.physics.uiowa.edu!math.ohio-

state.edu!news.cis.ohio-

state.edu!news.maxwell.syr.edu!newspeer.monmouth.com!intgwpad.nntp.telstra.net!new

s1.optus.net.au!optus!yorrell.saard.net!duster.adelaide.on.net!news.saix.saia.asn.

au!news.mtx.net.au!pppk56a-77.mtx.net.au

Xref: news1.icaen comp.sys.apple2:141876

David Wilson wrote in message ...

>Most any card you design with on-board ROM needs to decode all three

selects

>(DEVSEL, IOSEL and IOSTB) and generate chip selects for ROM, devices and

the

>data bus buffer. This tends to take quite a few LSTTL chips. My idea is to

>replace these with a single PAL/GAL (plus an 8 input NAND gate) to take

care

>of all this (including the CFFF disable function). It will also allow for

the

>use of RAM instead of ROM as this makes code development much easier.

>Any thoughts on this would be appreciated.

It is hard to imagine any significant project being undertaken which would

really benefit from this. It is almost impossible to get hold of devices (eg

EPROM) that would fit into the memory space (and those you do get, you

probably wouldn't want to use). Using larger devices would be a waste

without making available the rest of the memory which means using some form

of bank switching.

How generic is the PAL/GAL to be (since you're also adding a TTL device as

well)?

PLDs are becoming inexpensive and readily available. It would be easy enough

to produce a trivial PLD design which would decode everything (get rid of

the NAND gate), provide /CS lines and addressing for modern memory devices

(eg 128Kx8 --> 512Kx8) making the entire space available through the 2K

C800:CFFF window using an arbitrary location (eg C0[n+8]0) for the bank

Apple II Computer Technical Information : Apple II Family Hardware Info

ftp://ground.ecn.uiowa.edu/2/apple2/miscinfo/hardware : May 2001 : 174 of 572

1 2 ... 169 170 171 172 173 174 175 176 177 178 179 ... 571 572

Caple C871i Bedienungsanleitung Seite 174

Kommentare zu diesen Handbüchern

Caple C871i Bedienungsanleitung Seite 174

Kommentare zu diesen Handbüchern

Verwandte Produkte und Handbücher für Kochfelder Caple C871i