VGA output shifted left?

[Rodney Hester]

I've noticed my VGA output is shifted to the left - to what degree depends on the monitor I'm plugged into, but there's no VGA-compatible display I've tried where at least half a column on the left side wasn't cut off.

Is this a normal thing that can somehow be adjusted on some monitors or is it an indication of a problem with my port/soldering?

[Walt Perko]

Hi, 

Most if not all monitors can be adjusted in the menus to move the image left/right/up/down ... look in the "MENU" button on the monitor.

[Tom Wilson]

It would be nice if the back shelf was a little longer… is that possible, David?

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Tom Wilson
wils...@gmail.com
(619)940-6311 

[Belknap K]

Normal behavior.

I have one LCD that won't show all columns on the left.  The VGA signal is likely out of spec, from the design.

The other LCD I tried had a lot more adjustment in it from the front panel controls, and that one works quite nicely.

You do not need to 'fix' a thing .. but you won't be able to use that display, as things stand.

[Rodney Hester]

Thank you all for the explanation and suggestions!

[da...@hansels.net]

Tom,  I don't really know enough about the picture generation for Geoff's terminal to be able to give good
advice here. Looking at the source it seems there are some #defines in the "Video.c" file that could possibly
change the timings. But the PIC32 is hard pressed to produce a VGA signal so the length of the front/back
porches may be restricted by other constraints.

[Tom Wilson]

I'll take a look at the source when I get a chance. 

If there's any back porch at all after the horizontal sync pulse, then there should be a way to change the amount of time the system waits before drawing pixel data. It's been a while since I've looked at Geoff's VGA generation code (which I spent time looking at for the Maximite), but it might be worth re-visiting.

Tom Wilson
wils...@gmail.com
(619)940-6311 

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[bob olbrich]

Does this mean that the c***p Amazon/Chinese portable monitor I bought recently su**s?

It does not have an adjustment for this overscan problem. 

[Chris Davis]

Maybe, but I think it's more likely you just haven't found the setting yet.  I have a few of those and that setting is buried under levels of menus, and it might only be available while in VGA input mode.

On the one I have in front of me, I had to switch to VGA input, then click MENU > Picture Mode > MENU > Other Option > arrow down to Screen > right arrow > then I see "Horizontal Pos." and "Vertical Pos."

[bob olbrich]

I'm afraid I don't have "other option".

[Walt Perko]

Hi, 

Do you have the make, model, and a link to the seller of the monitor?  

What about a manual for the monitor?  

.

[Chris Davis]

Post some pictures of your menu(s).

[bob olbrich]

Hello again,

I found the screen adjustment "PC Setup" under "Picture" and 

off the bottom of the screen at first visit. As you predicted there are values 

for both horizontal and vertical adjustment. However, the horizontal value 

does not change the absent display of the first character and a half of any line.

I've sent two attachments showing this problem. I believe this has been

documented in the group. If you want more, let me know.I have to send them

separately.

By the way my Raspberry Pi 4 was having similar symptoms, but an OS

configuration change solved it.

[bob olbrich]

Here's the other pic.

[Tom Wilson]

Yup. This is a known problem, and it's related to the "back porch" in the PC firmware for the terminal chip. 

Someone who's familiar with PIC programming would have to dig in to the source code to see if it's possible to make the back porch 4 pixels longer (and adjust the front porch, the blank space on the right side) accordingly.

[bob olbrich]

FYI, it is a Thinlerain brand. Are there others beyond Eyoyo? At least Thinlerain

offered me a return. Any recommendations for a good 10" portable?

On Friday, August 15, 2025 at 5:51:45 AM UTC-5 John Galt wrote:

it also depends on the lcd monitor i never had this behavior with mine i have a bunch of really old 4:3 lcds and i was using them.  i have some of those EYOYO lcd monitors and those are garbage.

[Walt Perko]

Hi, 

I goto the local thrift store and buy VGA monitors for $5 to $10 ea.  I've gotten several DELL 17" to 24" monitors, and a couple of acer 24" monitors.  

.

[bob olbrich]

Sorry, I don't have the desk space for a larger monitor.

[Walt Perko]

Hi, 

I bought a 10" TV/Monitor for $3 at my local Thrift Store ... 

When I'm looking for something specific, I just visit the store once a week, let them know exactly what I'm looking for and even though it's rehab drug addicts working there, they make a note so whomever is working the computer section can see to either give me a call to let me know something came in, or they can put the note on the item so I have a chance to buy it first.  

.

[bob olbrich]

Surprise! Thinlerain has completed a refund with me, but does not want a return.

That's a first for me. If anyone wants to work on the proposed fix, I'd gladly donate

this monitor for the effort.  I don't know the priority that this fix might have.

Regarding thrift stores, Goodwill is about to open its largest store in my county.

It will be only a few miles down the road. I may drop  by.

[Walt Perko]

Hi, 

My DAZZLER output is to the right of center on my monitor ... it would be interesting to try the cheap-o with the DAZZLER ... it might work since you're losing stuff on the left side.  But they vendor didn't tell you to tweak the monitor on any POTs inside?  

.

[bob olbrich]

The exchange with the vendor was limited. More like "You are unhappy, we will refund."

[Walt Perko]

Hi, 

Just the other day I got a similar response from a vendor that was selling 20MHz Z80 CPU chips.  I got the chips earlier this week.  Put them on my Z80 tester ... one failed at 1MHz, 4MHz, 10MHz, 16MHz and 20MHz ... the other chip was missing one PIN ... 

I sent the vendor a photo of the failing chip and the chip with the missing PIN ... he sent me a return label and refunded me in full the same day.  

I think eBay has been cracking down on fake sellers and bad vendors and it's scared good vendors into acting fast so they don't get any bad hits and banned from eBay.  

.

[bob olbrich]

Success! Monitor #2 arrived today (Jinswy). It has no problem

with the left edge. Now I need to find an explanation for its

"forgetfulness" with regard to altered settings. I can change the

horizontal position (I don't need to, now), but as soon as I power down the setting

goes to its original value. The manual is no help, so its time

for another email.