Some questions about the IIsi

[PB145B]

I just recently got a IIsi (a machine I have wanted for quite some time) at Goodwill and I have been trying to learn all I can about it.

I have seen a few IIsi machines with no onboard ROM and a ROM SIMM installed. How rare are those? And also, can the ROM SIMM slot be used on the machines that already have onboard ROMs? Like to upgrade the ROM or something like that?

Why can the power button on the rear be turned and locked down? What is the purpose of that?

 

[Dog Cow]

Why can the power button on the rear be turned and locked down? What is the purpose of that?

I pass on all the above questions except this one. Purpose is to ensure the computer will restart in the event of a power failure.

 

[PB145B]

I pass on all the above questions except this one. Purpose is to ensure the computer will restart in the event of a power failure.

Ah, okay, cool! Thanks for answering one of my questions!

 

[MrGasS27]

I just recently got a IIsi (a machine I have wanted for quite some time) at Goodwill and I have been trying to learn all I can about it.

I have seen a few IIsi machines with no onboard ROM and a ROM SIMM installed. How rare are those? And also, can the ROM SIMM slot be used on the machines that already have onboard ROMs? Like to upgrade the ROM or something like that?

Why can the power button on the rear be turned and locked down? What is the purpose of that?

There are two pins on the IIsi for choosing beetween onboard ROM and SIMM ROM, if you short these the IIsi will boot from the SIMM ROM

 

[PB145B]

There are two pins on the IIsi for choosing beetween onboard ROM and SIMM ROM, if you short these the IIsi will boot from the SIMM ROM

View attachment 23387

Dang! That is really cool! I was wondering what those two pins were for.

Thanks for answering my question!

 

[MrGasS27]

Dang! That is really cool! I was wondering what those two pins were for.

Thanks for answering my question!

You're welcome, man

 

[tanaquil]

Ah, okay, cool! Thanks for answering one of my questions!

Thanks, indeed! I have been using a IIsi for years and never once noticed that. Now I know.