Update docs to refect removal of 12V Aux, and for branding changes

This commit is contained in:
Matthew Nielsen 2023-01-26 10:12:37 -07:00
parent 66fdeb5b0b
commit c9c1105d38
3 changed files with 18 additions and 38 deletions

View File

@ -1,20 +1,20 @@
# 1.4
## Component Changes
### Replace 12v aux power with 5v
## Replace 12v aux power with 5v
This change is for two reasons:
1) The 7805 regulator is wasteful, especially when the IIgs only has 2.5a on the 12v rail
2) The Apple IIe doesn't have a fan connector
2) Some models of Apple IIe don't have a fan connector, and most II/II+'s don't
The fix for this will be to get 5v directly from the Game IO (Paddle) Port, a direct tap on the 5V power supply wire, or from a card slot.
This 5v will be used directly via an IC that performs reverse current and over-current protection.
## Layout Changes
## Branding Changes
The current design has been retroactively branded "BlueGS / BP" to distinguish it from the upcoming RP2040-based "BlueGS / RP"
For a brighter LED, you have the option to choose
# 1.3.2
Move External LED connector closer to edge to clear cable plugged in to J1.

View File

@ -1,30 +1,10 @@
# Powering BlueGS
<!-- TOC -->
- [Powering BlueGS](#powering-bluegs)
- [Ways to power BlueGS](#ways-to-power-bluegs)
- [Termination Power from SCSI card](#termination-power-from-scsi-card)
- [Termination Power from another SCSI device](#termination-power-from-another-scsi-device)
- [+12V from the IIgs fan connector](#12v-from-the-iigs-fan-connector)
- [USB port on Blue Pill board](#usb-port-on-blue-pill-board)
- [What is Termination Power?](#what-is-termination-power)
- [What SCSI cards do/don't provide Termination Power?](#what-scsi-cards-dodont-provide-termination-power)
- [Cards that DO provide Termination Power](#cards-that-do-provide-termination-power)
- [Cards that DON'T provide Termination Power](#cards-that-dont-provide-termination-power)
- [Unknown cards](#unknown-cards)
- [How can I tell if my SCSI card is providing Termination Power?](#how-can-i-tell-if-my-scsi-card-is-providing-termination-power)
- [Why can't I use USB while BlueGS is powered from SCSI or +12V?](#why-cant-i-use-usb-while-bluegs-is-powered-from-scsi-or-12v)
<!-- /TOC -->
# Ways to power BlueGS
There are 4 ways to power your BlueGS board, listed here from "most easy" to "least easy".
## Termination Power from SCSI card
If your SCSI card provides [Termination Power](#what-is-termination-power), then all you need to is connect BlueGS to your SCSI card using the included flat 26-pin cable. No additional steps are required, and BlueGS should turn on the moment that the computer is powered up.
If your SCSI card provides [Termination Power](#what-is-termination-power), then you only have to BlueGS to your SCSI card using the included flat 26-pin cable or DB-25-M connector. No additional steps are required, and BlueGS should turn on the moment that the computer is powered up.
## Termination Power from another SCSI device
@ -37,19 +17,24 @@ Most external SCSI devices will provide the necessary Termination Power. To powe
This external device must be powered-on *before* the IIgs turns on.
## +12V from the IIgs fan connector
## +5V from inside the computer
You can power BlueGS using the IIgs's internal fan connector (or any other source that can provide from 6V DC to 12V DC).
You can power BlueGS via the "Aux 5V Power In" connector, using a 5V source in your computer. This can be from the Game IO port, a card slot, or a tap from the power supply rail.
If you power BlueGS using this connector, it will also send termination power to any other devices on the SCSI bus that may need it -- such as another BlueSCSI device!
**Note for v1.2 users**:
If you are using V1.2 of the board, it is recommended that you do **NOT** use 12V aux power for an extended period of time without attaching a heat sink to the regulator on BlueGS (chip labeled "AMS1117"). This warning does not apply v1.3 or higher of BlueGS.
Older versions of BlueGS could be powered by the 12V fan connector in the IIgs, but that has been removed in 1.4 and higher.
## USB port on Blue Pill board
You can power BlueGS using the USB connector on the Blue Pill module as long as you are not also using SCSI Termination Power or 12V aux power.
You can power BlueGS using the USB connector on the Blue Pill module as long as you are not also using SCSI Termination Power or 5V aux power.
### Why can't I use USB while BlueGS is powered from SCSI or Aux?
There is a design flaw on the Blue Pill board where power sent to the +5V pin of the board can then be sent *back* through the USB connector. This "backflow" can potentially cause damage to whatever is providing USB power and so it strongly recommended that you do not use USB to power BlueGS while connected to SCSI Termination Power or aux power.
If there is no termination power on your bus and BlueGS is not using the aux power connector, then there is no danger of "backflow" and USB power can be used.
# What is Termination Power?
@ -89,8 +74,3 @@ If your card is not in one of the lists above, then the easiest way is to connec
If you have a multi-meter, you can check the voltage on pin 25 of the DB-25 connector. If termination power is provided, this pin should read between 4.5 and 5 volts.
# Why can't I use USB while BlueGS is powered from SCSI or +12V?
There is a design flaw on the Blue Pill board where power sent to the +5V pin of the board can then be sent *back* through the USB connector. This "backfeed" or "backflow" can potentially cause damage to whatever is providing USB power and so it strongly recommended that you do not use USB to power BlueGS while connected to SCSI Termination Power or 12v aux power.
If your SCSI card does not provide Termination Power and BlueGS is not using the 12v aux power connector, then there is no danger of "backfeed" and USB power can be used.

View File

@ -1,6 +1,6 @@
# Blue-GS: Compatible Termination ICs
## Blue-GS v1.2
## Blue-GS v1.2 and above
Any of the following in a SOIC-16 package are compatible:
* UC5603