DayStar LocalTalk LT200

@6674.ADF DayStar LocalTalk/MCA AppleTalk Adapter - DayStar Digital

DayStar LocalTalk LT200 & FS100 Installation Manual (scan by Alexandros Paterakis)

LocalTalk LT200 Adapter
Changing Interrupt Level
Changing Port Address
ADF Sections

LocalTalk LT200 Adapter P/N 2271018-001 [P] (WIP outline, better photo needed)

JB1 3-pin jumper
JB4 2-pin jumper
U8 Zilog Z8018008PSC MPU
U11 pads for more SRAM?
U12 Sony CXK5864BP-12L 8Kx8 SRAM
U16 Zilog (ST) Z8530AB1 SCC
U22 Chips P82C611? MCA Bus Interface
U26 TI PAL? 0160601
U27 DIP-20 socket (PAL?)
Y1 18.432? MHz xtal
Y2 ? xtal

U8 Zilog Z8018008PSC 80180 MPU @ 8 MHz, DIP-64 package
U16 Zilog (ST) Z8530AB1 Serial Communication Controller (SCC), NMOS, Universal-Bus
   Dual channel, multiprotocol data communication peripheral (serial <-> parallel)

Huh, what are all the jumpers about?

Changing Interrupt Level

Power On Setup (POS) is a new feature introduced by IBM in an attempt to relieve the end user of being expected to configure option cards to function in their PC's. The PS/2 comes with a Setup\Reference diskette that contains software to dynamically configure the Adapters at installation.

The DayStar LocalTalk Board contains fixed resources that are configured in the following manner:

pos[0]=xxxx1001b    3 or Register 3
pos[1]=01000000b    Not User Addressable
pos[2]=00000011b    Not User Addressable
pos[3]=XXXX1010b    Not User Addressable

If there is an address conflict with other cards, Interrupt 3 (pos[0]) can be changed to eliminate the conflict.

To change the Interrupt, configure pos[0]=xxxx1001b, using EDLIN or any text editor, to the new interrupt level as follows:

XXXX1011B = Interrupt level 5
XXXX1101B = Interrupt level 6
XXXX1111B = Interrupt level 7

Re-configure your PS/2 using the new ADF file on the PS/2 Reference Diskette. The Autoexec.bat file must be configured to include the new interrupt command as follows:

DTALK (space) /Cardinit=x (x=the new interrupt level)

Changing Port Address

>Register 4 == 01000000B. The least significant byte of the port address. This is equivalent to 40H (hex). DayStar uses port address 340. This register is used in conjunction with Register 5, which is the most significant byte. Other address configurations, for example, are:

01010000B == 50H
01100000B == 60H
10100000B == AAH

Care should be taken that these addresses do not collide with other installed, or system hardware addresses.

ADF Sections

Ed. Tom: This has to be the most incompetent ADF I've ever seen. The adapter has POS registers, but they entirely killed that aspect by making all resources fixed, not telling the System Configuration what resources are actually being used, and making the user edit the ADF manually! How is this better than jumpers? I hope somebody was punished for shipping the card with this abomination. On the positive side, it should be easy to write a proper ADF for the card.


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Louis F. Ohland, Peter H. Wendt, David L. Beem, William R. Walsh, Tatsuo Sunagawa, Tomáš Slavotínek, Jim Shorney, Tim N. Clarke, Kevin Bowling, and many others.

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