MSX SCSI Interface

By SoRoS

Supporter (8)

SoRoS's picture

27-05-2011, 04:07


Does anyone have the schematics or photo (both sides) of any MSX SCSI interface based on WD33C93A?

I´m trying to find this about a month without lucky. Wink

Thanks a lot your help.

Ricardo Sartorato

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By Manuel

Ascended (16638)

Manuel's picture

27-05-2011, 19:49

I only have the manual, no schematics...

By SoRoS

Supporter (8)

SoRoS's picture

28-05-2011, 01:57

Thanks Manuel!

By SoRoS

Supporter (8)

SoRoS's picture

05-06-2011, 22:01

Thanks Frits9164!

Do you know what´s the 74LS123 is doing on the circuit?
The 74LS32 and 74LS688 are the port decoder but I have no clue with the 74LS123.

Thanks again!

By frits9164

Resident (64)

frits9164's picture

05-06-2011, 22:59


Dual Retriggerable One-Shot with Clear and Complementary Outputs
General Description
The DM74LS123 is a dual retriggerable monostable multivibrator
capable of generating output pulses from a few
nano-seconds to extremely long duration up to 100% duty
cycle. Each device has three inputs permitting the choice of
either leading edge or trailing edge triggering. Pin (A) is an
active-LOW transition trigger input and pin (B) is an active-
HIGH transition trigger input. The clear (CLR) input terminates
the output pulse at a predetermined time independent
of the timing components. The clear input also serves
as a trigger input when it is pulsed with a low level pulse
transition (
). To obtain the best trouble free operation
from this device please read the operating rules as well as
the Fairchild Semiconductor one-shot application notes
carefully and observe recommendations.

 DC triggered from active-HIGH transition or active-LOW
transition inputs
 Retriggerable to 100% duty cycle
 Compensated for VCC and temperature variations
 Triggerable from CLEAR input
 DTL, TTL compatible
 Input clamp diodes


By Ota231

Rookie (27)

Ota231's picture

06-06-2011, 04:54

Hi, I have a SCSI interface. this week I will send photos to your gmail on both sides of SCSI.

By SoRoS

Supporter (8)

SoRoS's picture

09-06-2011, 13:16

Thanks so much men...
I really need this... with the photos i can finish the layout.